I'm on record of saying that Michigan needs a DC with NFL experience so Michigan can continue running and tweaking the Ravens scheme that has worked for the last 3 years. We all remember Don Brown's defense and what a disaster that was.
The issue is that everyone else in the NFL wants to run the Ravens system and hired pretty much all of the top assistants out of Baltimore already. So now Sherone is considering Joe Cullen the current Chiefs DL coach and former Ravens DL coach. This guys has had 18 different coaching jobs between college and the NFL.