I love Stevens, but I don't think's above reproach. Especially when it comes to bigs. Perhaps the problem is that at Butler he never had any good big men, so his offense was predicated on perimeter oriented attack based off ball movement and shooting a lot of 3's (basically living and dying by the 3). So unless you're like Horford who combines 3 PT shooting with really good passing and can thrive playing on the perimeter, then you may not be the best fit for Stevens' scheme.
Sullinger
He comes to the Celtics and turns Sullinger, a very capable post player, into a 3pt shooter. His attempts rise from 0.1 pre-Stevens to 2.8 in Stevens' first year, while shooting 26.9%. The next year he shoots 28.3% on 3.2 attempts. So even though it wasn't working, he continued to let Sullinger jack up 3's. In fact, Sullinger was an excellent mid-range player before Stevens arrived (shooting 53% from 10-16 feet), but that aspect was taking away from his game.
Olynyk
Contrary to popular belief he was actually a pretty good post player in college, but that part of the game wasn't used in the pros. I won't harp on this too much since Olynyk is better suited on the perimeter, but Stevens did say something along the lines of wishing he had used him the way Spolestra is.
Baynes
He seems to want Baynes to start shooting 3's too. This season he's shot 9 so far (all misses), while only attempting 7 in his first 5 seasons combined (1 make). I just don't see this as Baynes' game, preferring that he plays to his strength and be in position to attack the glass to grab offensive rebounds, and it's more of a round hole / square peg approach.
Monroe
Far and away the best post player Stevens' has ever coached, but through 3 games (14 MPG) I do have my concerns about how he'll use him going forward. It just doesn't seem as though he's going to be a good fit in his system.
So is his system suited for bigs? Is he able to adapt based on personnel? Will he continue to play small ball for the sake of playing small, even though we have better bigs than we do wings?