How Involved Are Buy-Side Advisors Beyond Sourcing?

I’m curious what others have seen in the say sub-$25M deal space for deal execution support. From what I’ve observed, many buy-side advisory firms focus on sourcing, introductions, and diligence coordination, but I’m trying to understand how involved they really are beyond that. Are they actually driving the hands-on parts of the process: refining a thesis, identifying and engaging targets, helping build forecast models, analyzing working capital and debt coverage, and packaging deals for you to present to lenders and investors, or are they mostly coordinating around those steps? What is the scope around these engagements? For those who’ve worked with a buy-side advisor, how deep do they typically get in the execution and analysis side? Are they an extension of your team or more of a project manager? And if there is a gap here, who’s actually filling it?