Consider this scenario for the committee.
Wisconsin 13-0, Alabama 12-1, Georgia 12-1, Miami 12-1, Oklahoma 12-1, Clemson 12-1.
Who should they select?
In this scenario, the only team that is absolutely out is Miami. The only two teams absolutely in are Georgia and Clemson.
Clemson, having beaten a top-3ish, undefeated Miami team in order to win the conference title, with its other parts of its resume, is always making the playoffs in this scenario.
Georgia, having won the SEC and just beaten an undefeated, #1 Alabama team, is always in the playoffs in this scenario.
Miami is not getting in over Clemson in this scenario, and the ACC is not getting in two teams in this scenario. So they are out.
That leaves two spots for Wisconsin, Alabama, and Oklahoma. My money in this scenario is on Oklahoma and Wisconsin.