My question is if you give Stevens a B or a B- or a C+, what are you giving other contemporary coaches? Here are the champions for the seasons that Stevens was a coach:
SAS
GSW
CLE
GSW
GSW
TOR
LAL
MIL
Some of those coaches that won titles are Popovich, Jackson, Kerr, others are lesser known. I am not sure that Stevens coached any worse then these other coaches who had better players, better teams. Is Nick Nurse a better coach (TOR in 2019)? How about Tyronn Lue for CLE in 2016? How about Mike Budenholzer? Was each of these more about Leonard, Giannis, and LeBron or was it the coaching? Would you rather have had any of these over Stevens?
I think that if Stevens wanted to coach again, teams would line up to hire him. I think he was viewed as a top tier coach.