Michigan's challenge will be if they can develop an offense that can generate 20-28 points a game, control the clock and limit turnovers. Offensive line development and finding a big wide receiver target will play into that. The defense should be just fine. Maybe not quite as deep this coming season, but their front end starters will be elite.
Texas, Oregon, and Ohio will all be top 5ish teams. If they can steal one of those, they will be in position for a playoff bid. If not, it means running the table and hoping the B1G gets 4 - 5 invites to the dance. That would have happened this year with a 1 12 team playoff (Washington, Oregon, Michigan, Ohio, Penn State), albeit the conference wasn't together yet.