Well:
Since actual revenue share is both remarkably and uniquely traceable - and is required reporting on federal DOE documentation - and the limits are a hard cap determined by court order - that option is out the window.
"NIL"? One would have to define that, because the $$ being spent to buy players is most certainly not fair market value for their legitimate "Names Image and Likeness" usage.

That being the case, as it has been practiced these last several years, money from about anywhere, shipped to players by about any means or route desired, with no limits or tracking (which is also why that is where "the grifters live").
So - where do YOU think schools are getting that money? (Spoiler: Every program is different, and none are managed or subject to any meaningful oversight or in any way limited or subject to any controls. CSC, cough, cough)
It ain't that confounding.