Defense does win championships. Michigan's defense was very good. Nebraska was 5th in total defense 12th in scoring and 3rd in rushing defense. 28th in pass defense 12th in scoring defense. Turnovers gained 24.
On offense Nebraska was 1st in rushing, 1st in scoring (scoring 1 more than twice the number of TD's as Michigan. Turnovers lost 21.
19th in punt returns 11.8 per return with one TD. Net punting 74th. Kickoff returns 24.3 with no TD's (7th)
Average margin of victory 30.2 pts.
Michigan was 1st in total and scoring and 5th in rushing, 1st in passing defense turnovers gained 26.
Michigan was 44th in scoring offense and 44th in total offense, 27th in rushing offense. turnovers lost 17.
Punt returns 8.2 yd/return with 1 TD. Net punting 78th. Kickoff returns 20.3 with no TD's (58th)
Average margin of victory 17 pts.
Opponents: Nebraska beat teams rated (AP) 2,3,14,17 at the time the game was played. They beat teams rated 7,8,18,20,23 in the final poll
Michigan beat teams rated 2,4,8,8,15,15,23 at the time the game was played, but 9,12,16 in the final poll.
So. Michigan had a slight to moderate edge in defense, a slight edge in Turnovers. Nebraska had a big edge in offense and a slight edge in kicking game.
Quality wins is argued both ways. I would argue that the final AP poll is a better gauge of who beat the better teams. Michigan vs. Nebraska would have been a great game, but I suspect Nebraska would be favored on a neutral site and (of course) I think the Huskers would have won. That being said, I have no problem with the split title.