In many ways Wade does get a pass when maybe he shouldn't. That he's the Grandpa everyone wishes they had goes a long way. He has taken two defenses to a Super Bowl, which is life-long credibility.
On the other hand, does he have any surprises left? Aren't there miles and miles of film of his defenses to study?
My feeling is thus: Unlike an offense, which can do all sorts of fancy schemes and motions, and situational substitutions, the defense is more limited and must rely on talent. For various reasons, the talent isn't there on the defense, especially at LB.
My assumption, and I haven't seen most of our games, is that Wade has been keeping Suh and Brockers in check to compensate for the lack of talent at LB. This may be true of Joyner as well. Suh & Brockers are both penetrating DL, as is AD. Were he to unleash all 3, that would put a lot of responsibility on our under talented LB's. So he uses them to tie up the OL and let AD and his OLB's rush the passer. The problem is Suh & Brockers are wasted in the space eating role and neither are particularly good at it either. (Brockers was pulled off the nose last year) Meanwhile, AD is only one guy and we lack good rush from our OLB's. (Fowler is coming around).
Wade is doing the best he can with the wrong players at LB, and the DL playing the wrong role. The DB's are probably as solid as we can reasonably as for but lack depth. We're playing 9 on 11, and it's hard to win that way.