Pro's and amatuers. One gets paid another doesn't. Kind of sways the playing field. This isn't golf. This is big boy football. Injuries and no school bands. It's a fun idea but one that will never see the light of day.
Plus - let's face it what is the biggest difference in the pro game where 10% or less of college players make an NFL roster. It's speed and size. Take the worst NFL team whoever you want and put them against USC and see if USC is even within 14 points of them.