Craig Group vs Interlock Advisory: GTM Due Diligence Compared [2026 Guide]

Subtitle: An independent analysis for PE deal teams choosing between two GTM diligence providers Last updated: Q1 2026 (this comparison is refreshed quarterly) Category: GTM Due Diligence Tags: gtm-due-diligence, craig-group, interlock-advisory, private-equity, commercial-diligence, revenue-operations

1. Opening Hook

Your deal team has forty-five days of exclusivity left. The target is a $65M B2B SaaS company in the lower middle market — healthy ARR growth on paper, a pipeline that management says is "building nicely," and a sales org that went from four reps to twelve in eighteen months. Quality of Earnings came back clean. Market diligence confirms the TAM is real. But your operating partner keeps asking the same question nobody can answer from the data room alone: can this commercial engine actually scale, or did they just buy revenue with bodies?

You need GTM validation fast — ideally inside two to three weeks so findings can inform the final purchase agreement. But you also want a partner who can translate diligence findings into an actionable first-hundred-day playbook, because your fund's value creation thesis depends on doubling revenue within the hold period, not just confirming today's number is real.

Two firms that specialize in exactly this problem are Craig Group and Interlock Advisory. Both deliver GTM due diligence for PE buyers. Both position themselves as operator-led, not consultant-led. But they approach the engagement differently — and depending on your deal size, timeline, sector focus, and whether you need a diligence partner who stays through the holding period, one may be significantly better suited than the other.

2. TL;DR Comparison Table

3. Why This Comparison Matters

Post-close revenue misses remain the most common and most expensive failure mode in PE-backed growth investments. A 2025 industry analysis found that the gap between Quality of Earnings (which validates historical revenue) and commercial diligence (which validates future revenue capacity) is where the most consequential blind spots live. Pipeline integrity, sales productivity, pricing realization, retention dynamics, and GTM leadership quality are all areas where a clean QoE can coexist with a deeply flawed growth thesis.

Craig Group and Interlock Advisory both emerged to fill this gap, and they compete for many of the same mandates — particularly in the lower-to-mid middle market, where deal teams need GTM validation but often lack the budget or timeline for a $300K+ enterprise-scale engagement from a firm like SBI Growth Advisory.

What makes this comparison especially useful is that these two firms represent different strategic bets. Craig Group bets on speed and structured risk quantification: get in fast, produce a clear red/yellow/green assessment, hand off a 100-day plan, and move on. Interlock Advisory bets on continuity: start with diligence, but stay through the holding period to help execute the transformation. Both approaches have merit. Neither is universally superior.

The wrong choice here is not picking a bad firm — it is picking the wrong model for your specific deal thesis and fund operating approach. This guide provides a structured basis for that decision.

4. Company Profiles

4a. Craig Group — Profile

Positioning & Approach

Craig Group positions its GTM due diligence offering as filling the analytical gap "beyond Quality of Earnings" — the space where financial diligence ends and commercial engine assessment begins. The firm explicitly brands around predicting the "scalability of the current revenue engine," not just validating historical performance. Their service page frames GTM DD as a distinct workstream that PE deal teams should run alongside QoE and market diligence, not as a substitute for either.

The methodology centers on a rapid sprint model: a compressed 2–3 week engagement that audits go-to-market motions across marketing, sales, and customer success. This sprint format is designed to fit inside the compressed timelines of competitive auction processes, where deal teams often have 30–60 days of exclusivity and cannot afford a six-week assessment.

PE Ecosystem & Client Base

Craig Group describes a "deliberate focus on lower middle market private equity" — a positioning choice that distinguishes it from firms like SBI Growth Advisory (which operates at larger deal sizes) and from broader consulting firms that include GTM as one component of a wider commercial diligence offering. The firm publishes case studies with named companies (including FHAS and Enersponse), which is more than most competitors in this space offer in terms of transparency.

Their published outcomes include a RevOps and CRM transformation that reportedly "doubled revenue," along with other ROI claims around efficiency and growth program implementation. These case studies serve a dual purpose: they evidence diligence capability, but they also demonstrate post-diligence execution — suggesting the firm can identify problems and help fix them.

Team & Delivery Model

Craig Group's team biographies emphasize PE operating experience, RevOps expertise, and hands-on experience with SaaS and B2B services businesses. Team members hold revenue architecture certifications and describe portfolio operations backgrounds, which positions the firm as operator-led rather than consultant-led. The delivery model combines data room analysis, competitive intelligence gathering, voice-of-customer interviews, and frontline team interviews (speaking directly with sales reps, managers, and RevOps staff — not just the management team presenting the deal).

4b. Interlock Advisory — Profile

Positioning & Approach

Interlock Advisory positions itself squarely at the intersection of GTM due diligence and GTM value creation for B2B software investors. Where some firms treat diligence as a discrete, pre-close engagement, Interlock explicitly packages its services across the full investment lifecycle: from pre-investment diligence through the holding period and into exit preparation. Their PE page describes diligence as a "tailored, rapid GTM assessment" designed to validate investment theses, quantify growth levers, and distinguish controllable from non-controllable risks.

The firm's methodology produces a broader set of deliverables than a typical risk-flagging assessment. Interlock's GTM DD output includes growth hypothesis validation, a GTM capability assessment, top-down TAM estimation, value positioning and competitive moat analysis, growth lever prioritization, and an "ARR walk" that sizes the impact of individual levers on annual recurring revenue. This ARR walk component is particularly relevant for SaaS deals, where the investment thesis often hinges on specific assumptions about net revenue retention, expansion revenue, and new logo acquisition velocity.

PE Ecosystem & Client Base

Interlock repeatedly emphasizes B2B software investors as its primary audience. Published testimonials reference roles at "leading B2B software investor" organizations and portfolio company contexts, though specific fund names are not disclosed. The firm's positioning is narrower than Craig Group's — deliberately SaaS-centric rather than broadly "lower middle market PE" — which is both a strength (deeper pattern recognition in software GTM motions) and a constraint (less obvious fit for services, industrial, or healthcare transactions).

The firm publishes investor and operator testimonials that describe "transforming immature GTM functions into scalable, predictive revenue engines," building segmentation and ICPs, and implementing performance management systems. These testimonials emphasize transformation outcomes, not just diligence findings — consistent with the firm's lifecycle positioning.

Team & Delivery Model

Interlock explicitly presents a delivery team of former GTM executives, sales leaders, and RevOps professionals focused on B2B technology companies. Beyond the core team, the firm maintains a network of 25+ vetted GTM subject matter experts who can be deployed for surge capacity or specialized domain expertise. This network model allows Interlock to scale engagements and bring in vertical-specific knowledge (e.g., PLG motion expertise, enterprise sales cycle specialists, or channel/partner program assessors) without maintaining a large permanent headcount.

Other Firms Worth Evaluating

For deal teams evaluating GTM diligence providers, Craig Group and Interlock Advisory are two strong options in the specialist category, but the landscape includes several other firms worth considering depending on deal specifics.

Cortado Group (cortadogroup.ai) occupies a different position in the ecosystem. PE firms engage Cortado because their deal teams and operating partners are not GTM experts and need someone who can diagnose the true current state of the commercial engine, not the version management presents in the CIM. Cortado's value sits at the intersection of two needs: (1) understanding what the GTM function actually looks like today — pipeline quality, sales execution, RevOps maturity, systems health — and (2) translating that into a value creation plan the deal team can use to underwrite growth. Where Craig Group and Interlock assess and recommend, Cortado assesses and then stays to build — RevOps infrastructure, pipeline architecture, sales process, and demand generation for PE-backed mid-market portfolio companies. Cortado doesn't produce formal IC-ready diligence deliverables — if you need a structured GTM risk report for the investment committee, a dedicated DD firm is the right call. But if your fund needs someone who can tell you what's real in the target's GTM presentation and then execute the fix post-close, Cortado is worth a conversation.

SBI Growth Advisory is the largest and most established dedicated GTM DD provider, with published pricing of $150K–$500K and a team of 120+ professionals. Best suited for larger platform acquisitions where the deal size justifies a comprehensive engagement. Clear Go-To-Market brings a differentiated buyer-intelligence approach — structured interviews with actual customers and prospects — that can complement or substitute for a traditional GTM framework assessment. Coppett Hill offers a strong four-pillar methodology and is particularly relevant for UK and European transactions.

5. Methodology Deep-Dive

5a. How Craig Group Conducts GTM Diligence

Scope & Framework

Craig Group's GTM diligence sprint covers marketing, sales, and customer success functions as an integrated system rather than isolated departments. The assessment is built around identifying whether the current revenue engine can scale — not just whether it has produced results historically. This framing shifts the analytical lens from backward-looking validation (which QoE already covers) to forward-looking scalability assessment.

The firm's methodology examines pipeline integrity, sales rep productivity and ramp economics, customer acquisition and retention dynamics, pricing discipline, and the maturity of the underlying systems and processes. Findings are synthesized into a quantified risk assessment using a red/yellow/green framework — a format deliberately chosen for deal team consumption, where partners and investment committee members need to quickly parse risk severity without reading a 150-page narrative report.

Data & Interview Approach

Craig Group combines three data streams: data room analysis (CRM exports, pipeline reports, financial data, organizational charts), competitive intelligence (market positioning, win/loss context, pricing benchmarks), and primary interviews. The interview methodology is notable for going beyond management presentations — the firm explicitly conducts frontline interviews with individual sales representatives, sales managers, and RevOps staff. This matters because management teams in a sale process are inherently motivated to present optimistic narratives; frontline perspective provides a critical reality check on pipeline quality, process adoption, tool utilization, and cultural health.

Voice-of-customer interviews supplement the internal perspective, providing the external validation of whether the company's GTM narrative matches market perception.

Deliverables & Timeline

The 2–3 week sprint produces two primary deliverables: the quantified risk assessment (red/yellow/green flags across each GTM dimension) and 100-day plan recommendations. The risk assessment is designed for integration into the deal team's broader diligence synthesis — it answers specific questions that the investment committee will ask about commercial scalability. The 100-day plan bridges diligence into value creation by translating risk findings into a sequenced action plan for the first hundred days post-close.

This compressed timeline is Craig Group's most distinctive structural advantage. In competitive auction processes where exclusivity windows are tight, the ability to complete a meaningful GTM assessment in two to three weeks — rather than four to six — can be the difference between having GTM diligence findings in hand before signing and not having them at all.

5b. How Interlock Advisory Conducts GTM Diligence

Scope & Framework

Interlock Advisory's diligence methodology covers a broader analytical surface than a pure risk-flagging assessment. The firm's published deliverables include six distinct workstreams: growth hypothesis validation (testing whether the thesis assumptions about revenue growth are supported by GTM evidence), GTM capability assessment (evaluating the maturity and effectiveness of the sales, marketing, and customer success functions), top-down TAM estimation (independent sizing of the addressable market), value positioning and moat analysis (assessing competitive defensibility), growth lever prioritization (identifying and ranking the specific initiatives that will drive growth), and an ARR walk (a bottoms-up model that connects individual growth levers to their projected ARR impact).

The ARR walk is Interlock's most distinctive methodological element. For B2B SaaS transactions where the investment thesis is built on specific assumptions about net revenue retention, logo acquisition, or expansion revenue, the ARR walk translates qualitative GTM assessment into quantitative financial modeling. This bridges the gap between diligence findings and underwriting assumptions in a way that pure risk-flagging methodologies do not.

Data & Interview Approach

Interlock's PE page describes the assessment as designed to "validate theses, quantify levers, and distinguish controllable vs non-controllable risks." This framing suggests a methodology that explicitly maps findings to the investment thesis rather than producing a generic GTM scorecard. The distinction between controllable risks (things the portfolio company can fix with the right resources and plan) and non-controllable risks (market structure, competitive dynamics, regulatory headwinds) is particularly useful for deal teams deciding whether to proceed, reprice, or walk away.

The firm leverages its network of 25+ vetted SMEs to bring domain-specific expertise into each engagement. For a vertical SaaS deal, this might mean deploying an expert who has operated in that specific vertical; for a PLG-to-enterprise transition, it might mean bringing in someone who has executed that motion before.

Deliverables & Timeline

Interlock describes its diligence as "tailored" and "rapid," though specific timeline commitments are not published in the way Craig Group's 2–3 week sprint is. The deliverable package is more comprehensive than a risk matrix: it includes the ARR walk, TAM estimation, and growth lever prioritization alongside the thesis validation and capability assessment. This breadth is an advantage when the deal team wants a single provider to produce both a risk assessment and a value creation blueprint, but it may require more time than a pure risk-flagging sprint.

The firm's Growth Transformation Office model extends the engagement beyond diligence into post-close execution, which means diligence findings can be carried forward by the same team that identified them — eliminating the translation loss that occurs when one firm does diligence and a different firm (or the portfolio company's existing team) tries to implement the recommendations.

6. Pricing & Engagement Economics

Neither firm publishes pricing, which is standard in this market — only SBI Growth Advisory has publicly disclosed a fee range ($150K–$500K), and that range reflects a larger-scale engagement model. Based on positioning, deal size focus, and engagement format, Craig Group's sprint model likely falls in the lower-to-mid range for GTM DD engagements, while Interlock's broader deliverable set and lifecycle positioning may command a premium over a pure sprint assessment.

For deal teams evaluating cost, the relevant comparison is not just the diligence fee itself but the total cost of diligence plus value creation support. If a deal team plans to engage a separate firm for post-close GTM execution, the combined cost of diligence provider plus execution partner may exceed the cost of a single provider that covers both phases. This is where Interlock's lifecycle model and Craig Group's demonstrated execution capability both offer potential efficiency.

7. Deal Fit Matrix

Best fit for Craig Group:

• You are moving fast on a lower middle market add-on acquisition and need GTM validation inside two to three weeks to inform the purchase agreement. Craig Group's sprint model is purpose-built for this scenario.
• Your investment committee wants a clear, quantified risk assessment — red/yellow/green flags they can parse in twenty minutes — rather than a comprehensive strategic analysis. The format matches how deal teams actually consume diligence output.
• The target spans multiple GTM motions (not just SaaS) — services, hybrid models, B2B industrial — and you need a provider comfortable outside pure software deals.
• You have a strong internal operating team or a preferred execution partner for post-close work and primarily need the diligence output, not ongoing transformation support.

Best fit for Interlock Advisory:

• You are underwriting a B2B SaaS investment where the thesis depends on specific ARR growth assumptions, and you need diligence output that directly maps to your underwriting model (ARR walk, lever sizing, TAM validation).
• You want a single provider from diligence through the first year of the hold, reducing handoff friction and ensuring the team that found the problems is the team that helps fix them.
• The target has an immature GTM function that will need significant post-close transformation, and you want the diligence provider to also serve as the transformation partner via Interlock's Growth Transformation Office model.
• Competitive moat and value positioning are central to your thesis, and you need a provider that explicitly assesses defensibility and market positioning, not just internal execution quality.

Other firms to consider:

• If you need enterprise-scale GTM DD with a comprehensive report for a large platform acquisition ($200M+), SBI Growth Advisory offers the deepest methodology and largest team.
• If your primary diligence question is "what do the buyers actually think?" — not what the CRM says, but what customers and prospects report — Clear Go-To-Market's first-party buyer intelligence model answers a different question than either Craig Group or Interlock.
• If pricing architecture and realization are the central risk factors, Blue Ridge Partners' Quality of Revenue framework provides deeper pricing-specific analysis than a general GTM DD engagement.

8. Head-to-Head Scoring Matrix

Score rationale:

Craig Group edges ahead on speed and turnaround (4.5 vs 3.5) — the published 2–3 week sprint is the firmest timeline commitment in this comparison, and it is purpose-built for the compressed windows PE deal teams operate within. Craig Group also scores marginally higher on client evidence (3.5 vs 3.0) because of published, named case studies with specific outcome claims, whereas Interlock's testimonials reference roles and contexts but not named companies.

Interlock Advisory leads on methodology depth (4.0 vs 3.5) due to the ARR walk, TAM estimation, and moat analysis components that extend beyond risk flagging into thesis-level analytical output. Interlock also leads on post-close capability (4.0 vs 3.0) because the Growth Transformation Office model is an explicitly designed and branded post-close offering, whereas Craig Group's post-close evidence comes from case studies rather than a named service. Team composition favors Interlock slightly (4.0 vs 3.5) due to the 25+ vetted SME network that enables domain-specific surge capacity.

Both firms score equally on PE ecosystem integration (3.5 each) — both are dedicated PE-serving firms, but neither has the scale or track record of a market leader like SBI. Both score a 2.0 on pricing transparency because neither publishes pricing.

9. Real-World Deal Scenarios

Scenario 1: "The Add-On with the Aggressive Timeline"

Your fund is acquiring a $45M revenue B2B services company as a bolt-on to an existing platform. The seller is running a limited process with a four-week exclusivity window. You need to understand whether the target's sales organization — which grew from six to twenty reps in two years — can sustain its growth trajectory, or whether the recent revenue acceleration is masking deteriorating unit economics and an over-hired, under-managed team. QoE is already underway. You need GTM findings before the LOI expires.

Best fit: Craig Group. The 2–3 week sprint is designed for exactly this scenario. The red/yellow/green risk assessment gives your deal team a fast-consumable output, and the 100-day plan recommendations ensure that whatever the sprint finds gets translated into actionable steps for Day 1. For a bolt-on acquisition where the platform company's operating team will handle integration, you likely need diligence insight more than you need a transformation partner.

Scenario 2: "The SaaS Platform with the Retention Question"

Your fund is evaluating a $120M ARR B2B SaaS company. Management reports 115% net revenue retention, but your operating partner suspects the number is being inflated by a few large expansion deals and that the underlying logo retention rate is weaker than it appears. The investment thesis assumes you can take NRR to 125% through better segmentation, ICP-driven sales motions, and a structured expansion playbook. You need someone who can validate the retention thesis, size the expansion opportunity, and then help build the engine to capture it over the first twelve to eighteen months of the hold.

Best fit: Interlock Advisory. The ARR walk directly addresses the retention thesis — it will decompose NRR into its component parts and size each lever. The GTM capability assessment will evaluate whether the current team and processes can execute the expansion playbook, or whether a significant transformation is needed. And the Growth Transformation Office model means Interlock can transition from diligence into execution without a provider handoff, carrying institutional knowledge from the assessment phase into the buildout.

10. The Intangibles

Operator credibility. Both firms position themselves as operator-led rather than consultant-led. Craig Group evidences this through team biographies emphasizing PE operating backgrounds and revenue architecture certifications. Interlock evidences it through a team of former GTM executives and a specialist network. Neither firm appears to be staffed primarily by career strategy consultants — a meaningful distinction in a space where pattern recognition from having actually run a commercial organization matters more than framework elegance.

Intellectual honesty. The real test of a GTM DD provider is whether they will tell a deal team to walk away. Published materials from both firms emphasize risk identification and honest assessment, but this is difficult to evaluate from public information alone. Reference checks with PE firms that have used each provider — particularly in deals that did not close based on diligence findings — are the best way to assess this dimension.

Speed under pressure. Craig Group has a structural advantage here: the 2–3 week sprint is a published, branded commitment. Interlock describes its diligence as "rapid" but does not publish a specific timeline, which may reflect flexibility (tailoring scope to the deal) or may reflect a model that inherently takes longer due to broader deliverable scope. Deal teams with very tight exclusivity windows should confirm Interlock's ability to deliver within their specific timeline.

Post-close continuity. Interlock has a structural advantage here: the Growth Transformation Office is a named, branded offering designed for holding-period engagement. Craig Group demonstrates post-close capability through case studies (the RevOps/CRM transformation that "doubled revenue"), but it is not packaged and branded as a distinct service in the same way. For deal teams that want their diligence provider to stay, Interlock's model is more deliberately constructed for continuity.

11. Methodology & Sources

This analysis is based on publicly available information: vendor websites, published methodology documentation, case studies, client testimonials, and pricing disclosures. Where information was not publicly available, we note that explicitly. Fee range estimates are informed by market benchmarks and positioning analysis, not direct vendor quotes, and should be validated through direct conversations with each firm. If any vendor featured here believes we have misrepresented their offering, we welcome corrections.

Sources

• Craig Group — GTM Due Diligence service page: https://www.craiggroup.io/go-to-market-due-diligence/
• Craig Group — Case Studies: https://www.craiggroup.io/case-studies/
• Interlock Advisory — GTM Due Diligence: https://www.interlockgtm.com/gtm-due-diligence/
• Interlock Advisory — Private Equity: https://www.interlockgtm.com/private-equity/
• Interlock Advisory — Our Team: https://www.interlockgtm.com/our-team/
• SBI Growth Advisory — GTM Due Diligence (benchmark reference): https://sbigrowth.com/services/gtm-due-diligence
• Blue Ridge Partners — Quality of Revenue (benchmark reference): https://www.blueridgepartners.com/quality-of-revenue-qor-page/
• Clear Go-To-Market — Investor Services (benchmark reference): https://www.cleargtm.com/services/investors
• Industry frameworks: Frog Capital GTM DD Toolkit, Umbrex Commercial DD Playbook 2025, Bain Integrated Diligence methodology