I agree with what has been said so far. If M&A modeling is not present in house, then it can be outsourced to M&A advisor. However, in more complex transactions, there are sometimes reasons why this is a difficult task and/or something to want to avoid. If there’s a need to build an operational model to estimate synergies, even if bound by confidentiality, sometimes, the buyer might want to keep details of it’s operations as secret as possible. Also, some industries might require specialized modeling skills, e.g. infrastructure assets, insurance and banking, etc.