Sure you have to assume that Stevens, who had no frontcourt and limited talent in general, "had" to maximize Jae's talent...and he did. Thomas and Crowder matched each other well and became a large part of the "little engine that could" last year.
I will insist on this...I always saw Jae Crowder as a bench player. Probably a sixth man. When he came here I felt that if Crowder was the sixth best player on the team you'd have good team...not a starter.
As far as the Cav's go, I haven't watched their games this year. I know from the past that Lebron is essentially a player coach in a role similar to what Russell was given by Red. Tyron Lue is not truly responsible for the conduct of the team on the floor, Lebron James is. This dynamic assures that Jae Crowder's talents will not be maximized in any way and losses will result in finger pointing/scapegoating/benching/position swapping and what have you as, there isn't the structure offered by a team that is run by a head coach whom is directly responsible for wins and losses.
Kyrie Irving, a top player in the league, arrives in Boston, a team that he has crushed for years and, without blinking, promptly changes his game to suit the head coach. All players, including Crowder, play better under great leadership...ask Red Auerbach.
We get high on our own guys and that is normal, but, last year's team couldn't beat any of the top 6 teams in the NBA and how could they? They were doing it on sheer effort and purpose and Crowder was all of that.