I'm not against Anthony Bennett as a player, but he wouldn't get many minutes in Boston. He'd be in the same situation as in Minny - receiving 10-15 minutes per game at most, and not being able to establish any rhythm. He needs a defined role to increase his confidence and development at the NBA level, but there's no way that's happening with the logjam at PF the C's have (especially with talks of Love and LMA).
I will say Stevens is radically different than Saunders in that he gives minutes to the better player, regardless of contract, experience, etc. So if Bennett were to play better than Olynyk/Sully/etc., there's a chance he could supplant them, but I don't see it happening.