It appears that successful coaches are so-called gurus in one aspect of the team. Some are offensive gurus such as Urban, while some are defensive gurus such Saban. Is there any successful program where the coach is not really good in one aspect of the football? By the way, this seems to be more of a case in college football than in NFL where there are many so-called CEO coaches (e.g., Harbaugh brothers).
In case of UM it seems that both Bo and Carr where the CEO types while RR was the guru. Hoke is obviously the former.