developing the players we have on the team,
Not that you said this but something I want to point something out.
You don't develop players by giving them playing time. Players are developed through coaching off the court not playing on the court. Players are developed in practice, in the weight room, in the video room, through studying and repetition. Once players can prove they can do the things they have to do in those areas, they are rewarded with playing time and execute all the things they have learned in their development.
I don't think there is a professional coach anywhere in the world who doesn't think this way.
At times through injuries, suspensions, roster creation, etc., does it become necessary for a coach to throw players into games that do not deserve playing time? Sure.
But if you think Stevens will be playing Olynyk, Sully, Melo, Iverson, Pressey and other super young players to develop them, I think you will be very disappointed when you see Humphries, Bogans, Wallace, Bass, and Lee getting regular rotation minutes. Why? Because they will be better than the young guys and adjust to new systems and the expectations of what the coach wants faster and better than some, most, if not all of the young guys.
I forget who said it -- maybe it was David Thorpe -- but playing time is the "royal jelly" for young players. You absolutely develop players like giving them playing time. That's the most effective way of improving them.
However, if you'd read what I've said before multiple times in this thread, I don't expect Stevens to play less deserving young players ahead of established veterans just for the sake of development. Stevens should expect guys to earn their minutes. I wouldn't have it any other way.
Again, I see this as an issue Ainge has to deal with -- if he wants certain guys to get more playing time, he has to clear the way. If he gives the coach a roster with a lot of competition for playing time between veterans and young guys, he'll need to accept that the coach will figure out his own rotation.