16 is overkill for football. Keep it 4 or at most 6 (like conference playoffs in NFL, top 2 get byes)
Oregon vs TCU
Auburn vs Wisconsin
would be good enough, and most years there are 4 worthy teams at the end.
Unfortunately teams like Ohio St, OU(Texas on a good year), and SEC runner ups always finish fringe top 8 and they control college football, so if there ever was a playoff it would have to be 8-16 teams so all those schools could be included most years.