Two things...
1. There is school NIL money. About $21 million for everyone, but you gotta split it across the sports. I'd guess most schools have about $15 million allocated to football, some to basketball, and some other sports. This is the settlement money pool. After that, there is outside NIL money, the stuff that is supposed to go through the clearinghouse. The only way Illinois or Maryland or anyone goes above the first $21 million is through outside clearinghouse deals. Schools can help advise collectives and do other things to increase the outside pool, but at the end of the day, there's a layer between the school and the outside pool. This means, among other things, that there is a whole lot of bullsh!t in numbers you read about the school's "budget" because it's not really the school's money.
2. I am surprised at the proliferation of assistant coaches. I'm an old econ guy so forgive the lingo, but if memory serves, when there are regulation-generated economic profits to be had, such as those that existed when the return to having great players couldn't be paid to the players, the rents should flow to the most inelastically supplied (hardest to duplicate) inputs. That meant elite coaches and elite program facilities. Now that you can pay players, rents should fall (and I expect the facilities arms race will be over soon), but I'm absolutely baffled that assistant coach salaries are taking any resources that could flow to an NIL pool. I'd be pushing every donor into the NIL collective program that I could, rather than trying to build the number of people on my staff.