I heard Bear Bryant say once "great players can make any coach look great no matter what the coach does to mess it up". I believe if Pees had more talent he would look better to us. OTOH, there were many times when an aggressive calculated risk would/could have saved the day. Also, if adjustments were made during games, they were done so transparently and without significant effectiveness, at least to my eyes.
Pees, imo, could have done better.
**** LeBeau, former DC of the Steelers, also ran a 3/4 but his version attacked the offense relentlessly. Pees ran the "bend but dont break/ read and react" 3/4 (more like the original Bullough version). BB has been successful with the latter both with the Giants, the Jets and now the Pats.
One major diff I see is that when "Bruschi's" Pats needed a stop, they attacked and got the stop more often than not.
Did Pees have complete say over the defensive scheme? I dont know but I doubt it. But if he had come up with a great idea to help the D, BB would most certainly have allowed its implementation.
Ultimately, lack of ideas is what did Pees in.