Take Texas for example, Clemson will be one of the toughest opponents they have played all year. Clemson might be on a par with A&M, better than Michigan, not as good as UGA (which Texas recently played to a draw). And Clemson may be the weakest team in the playoff.
Take Tennessee as well, they had Alabama at home and UGA on the road and then not very much to compare with Ohio State, an 8 seed. Or take Ohio State, they beat PSU and nearly beat Oregon and handled Indiana, three teams as good as or better than Tenn, but the other 9 games?
These favorites need to forget they are favorites, these are all capable opponents relative to most previous opponents.