http://www.basketball-reference.com/teams/BOS/2016/lineups/

If you look at our 5 man combinations in descending order for minutes played, the team of IT4, AB, Crowder, Sully, and Amir far and away has more minutes played (284 mins).  Their net rating is +3.9, which in my view is pretty good given the sample size.  So it looks like we have a fairly settled starting/finishing 5.

Here is what I would do permanently from here on out:  I would make Tuner the first sub off the bench, for Sullinger, and move Crowder to the 4.