Michigan played five other schools that are in this top twenty five last year. Those schools would be Notre Dame (24), Michigan State (12), Nebraska (19), Ohio State (18), and Virginia Tech (11). In those five games, Michigan went 4-1, with the only loss being at Michigan State, who beat Wisconsin in the regular season. Michigan did go 11-2 last season, so they beat some quality teams.
Yes, I am a Michigan fan, but I disagree with you on them being "WAY" overrated. 9 might be a little high to some people, but they're up there in that area, the 9-13 range. Preseason polls are just guesses anyways, after week one it'll look completely different.