We may have A LOT of defensive linemen - numberwise. Time will tell how good this unit ends up becoming. I am torn on the question of Kirk being able to turn this thing around for the third time. While I completely support all of the coaching changes that have taken place, it also can indicate Kirk is scrambling. And when you are scrambling, sometimes that is not the best position to be in ...
Soup was brought in and the WRs promptly got MUCH better at downfield blocking. Both DJK and McNutt became very good downfield blockers. That said, my guess is that GD feels the WR corps "knows" downfield blocking well enough that it's no longer a concern. But, the catch-and-run is not something Soup ever coached at Michigan or Iowa, so GD wants someone who CAN and HAS worked with that.
As to other changes, my guess is that some of it is mutual and some is "going in new direction, these are changes you have to make if you want to remain"-type stuff.
While I'm not that confident of getting to a bowl game, I'm convinced we won't be nearly as bad as we were in 2012. Much of it depends on OL and health of DL and LB. If those units stay healthy, we can easily win 6 games, IMO.
The running game doesn't concern me. Between Weisman, Bullock and Canzeri at RB, Rogers at FB with Weisman "available" there, too, we should be fine. QB and WR and how they can "mesh" will be the biggest issue on the offensive side of the ball. If we don't go vertical with any effectiveness, catch-and-run won't be very good no matter who is "throwing" or "catching", thus, "-and-run" won't be a factor.