Yeah, but you have to evaluate them in context of the players they have, for one. It's all relative.
Cutcliffe, for instance, gets an A++++ for QB coaching. He took a kid that didn't understand the game and tranformed him into one of the best QBs in the nation over the course of one spring.
Brooks, on the other hand, had his two starting DTs either gone from early defection or turning pro. His next two were a kid back from a two year mormon mission and a walk-on with no talent. The best player he has is a converted DE. So, if we evaluate him using the bar of recent/standard DT performance, then it appears he's done a bad job. But that ignores what he had to work with. He also has a tremendous record of, not only putting players in the pros, but preparing them to excel once there.
...stuff like that.