Here is a theory. Urban understands all of these issues addressed above but wants to take a systematic non-alienating approach. He began addressing issues with seeing Schiano take the Tennessee job and hiring breath of fresh air in Grinch (oops). Then he decided to not offer raises to Davis and Smith in the spring, suggesting they find work somewhere else (doesn't address Stud). My guess is he is trying to take the Saban approach to hire COO's of offense and defense. Had he been more decisive and less "kind" he would have cut Davis and Smith loose and not allowed Schiano to return, and we would be having far different conversations right now. I'm sure that keeps him up at night, but not convinced he wants to change his approach. Otherwise, he would have cut Davis loose mid-season.
Needless to say, the plan backfired with Schiano and Smith fiascos. Now he is trying to piece things together with a DC whose confidence is shaken and then the preseason happens. I know none of this is new or surprising but having a disaster in the offseason is though, but typically salvageable. Disasters in season are irreparable.
He is just trying to keep his head above water, all with a health issue.