There was a comment left in the Mailbag post about Rich Roriguez keeping his job regarding the dispersion of coaches on Michigan's team. Commenter TriFloyd brought up an issue with the fact that Michigan has 5 offensive coaches, 4 defensive coaches (one of whom doubles as the special teams coordinator), and a head coach that concentrates heavily on offense. What better way to address this potential imbalance than seeing how other Big Ten teams do it?
Illinois: 5 offensive, 4 defensive, 1 head coach
Indiana: 5 offensive, 4 defensive, 1 head coach
Iowa: 5 offensive, 4 defensive, 1 head coach
Michigan: 5 offensive, 4 defensive, 1 head coach
Michigan State: 5 offensive, 4 defensive, 1 head coach
Minnesota: 4 offensive, 4 defensive, 1 head coach
Northwestern: 5 offensive, 4 defensive, 1 head coach
Notre Dame: 5 offensive, 4 defensive, 1 head coach
Ohio State: 5 offensive, 4 defensive, 1 head coach
Penn State: 5 offensive, 4 defensive, 1 head coach
Purdue: 4 offensive, 4 defensive, 1 special teams, 1 head coach
Wisconsin: 5 offensive, 4 defensive, 1 head coach
Conclusion: Yeah, everyone does it this way. With the exception of Purdue and Minnesota, every team in the Big Ten has five coaches dedicated to offense, four dedicated to defense, and a head coach. Purdue has the luxury of not devoting a specific coach to the tight ends, since the TE position is virtually non-existent in their offense. Minnesota is in the unique position of having only nine coaches right now, since head coach Tim Brewster was fired a couple weeks ago; prior to Jeff Horton's promotion to head coach, he was an offensive coach, too. So the Golden Gophers are essentially in the same boat as all but Purdue.
Those head coaches lean in different directions. For example, Rodriguez leans heavily toward offense. I would assume that Pat Fitzgerald at Northwestern spends more time with the defense, considering he's a former linebacker. Joe Paterno just leans kinda forward because he's 114 years old and gravity does that to you after awhile.
I failed to research this adequately, but in skimming the coaches, it seemed that any designated special teams coordinators also leaned toward being defensive coaches. Except for field goals, you mostly want guys who will fly around and hit things going at a high rate of speed; punt coverage teams, kickoff teams, and kickoff return teams all have to have guys with no regard for their own health. Offensive linemen are too slow to be involved in 75% of special teams play; wide receivers typically aren't big hitters; and quarterbacks don't play special teams unless they're the holder for field goals and extra points. That leaves tight ends, running backs, and all manner of defensive players to fill out the vast majority of special teams units. So it makes sense that the coaches who work with those defensive players would be put in a position to coach special teams.
The fact is that offense takes more time to develop. It's about timing, working together, and execution. Every unit has to work at the same speed or the hole closes before the running back gets there, the quarterback doesn't get to his drop in time, the wide receiver makes his cut too early, the running back doesn't give his blocks time to develop, etc. Defense is mostly about effort, reaction speed, and flying to the football. Offensive players need more coaching. I realize that may not be the case with this team right this minute - and it might have behooved Coach Rodriguez to devote one more coach to defense this year with this many freshmen playing - but it's not like Rodriguez is doing something crazy here.
In summary, having "too many offensive coaches" is a red herring. It's the same everywhere. I've seen this issue brought up several times, not just in TriFloyd's comment, so I thought it was worth addressing. Look elsewhere for reasons that this team isn't succeeding.