If Cincinnati and Notre Dame both finish as 1 loss teams, Cincinnati would be ahead of Notre Dame for the same reason Oregon would be ahead of Ohio State.
Cincinnati even as an undefeated still needs some help. The Sooners are out of the picture and won't pass Cincinnati from behind, but Cincinnati still has to pass some people. If Alabama, Georgia, Oregon, and any 1 of the Big Ten trio finish as one loss teams, then your four playoff teams will be Georgia, Alabama, Oregon, and the Big Ten Champion. Cincinnati got some help when Baylor sent the Sooners to the grave but they need some help ahead of them.
Also, they won't make the playoffs as they have 3 losses, but a shout out to Wisconsin for doing a fantastic job of turning their season around. After starting 1-3 with a couple of blowout losses, the Badgers have won 6 in a row and are playing excellent football. Perhaps Wisconsin could get something like the Citrus Bowl or the Outback Bowl.