What's to stop the College's from funneling "leftover" revenue sharing money to company's that will then turn around the use it for NIL?

This may not apply to some of the smaller conferences, but let's take the SEC teams as an example. There is a known money advantage with the SEC teams where they will get, say, $100 million per team whereas ACC schools only get $50 million (I don't know the exact numbers, but there is a clear discrepancy). But across all Colleges, every college has to adhere to the $20.5 million revenue sharing cap. Thus, the SEC teams will have a surplus of funds to channel elsewhere (facilities, etc.). However, what is to stop those schools from hiring a company to perform work at the college or for the athletic department (i.e. provide food for the team, cut the grass, etc.) at some inflated rate with the expectation that the owner of that company, who happens to be a fan/alumni/donor turns around and uses the extra earnings to contribute to NIL and pay a player. So in a round about way, this NIL money was originally from the college. It just flowed through a few different channels and hands first.

Essentially, you may see the Athletic Departments start using a lot of local or "family owned" businesses for food, catering, clothes, gear, etc. so that the money makes it way back to the players. Thus, seems like Clemson's number 1 priority with spending any kind of money should be to use Clemson Alumni companies when ever possible.