"Eventually"? We split the teams in 1998, then all but solidified that split in 2014 creation of the CFP while relegating even more teams by removing the Big East from the equation. Thankfully, TCU was one of the handful of teams that was able to jump from the lower tier to the higher tier...
I could be wrong, but I think just signing the players to contracts to each team would solve this issue pretty quickly. For some reason, the NCAA has decided that's their Meatloaf. They would do anything for the game, but they won't do that.