Both teams like to play small, because it plays to their strengths mostly, because they lack size at 5 position and there's no true center in the east except for Andrew Bynum. I've been reading online that Erik Spolstra is considering starting Bosh at the 5 much like Doc Rivers did with Garnett.
Having guys like Bosh and Garnett at the 5, spreads the floor, because other big men can't run out. There's a reason why last season's ECF was competitive because both Miami and Boston went with small line-ups through out the series. Some would like to believe other, as if some how Bosh' injury played a role in the ECF going 7, but that's a false argument, because during the regular season when Bosh was in the starting line-up the Celtics won those 3 games easily, just saying.
I think Green can put a body on him, but actually blocking Bosh's shot we'll have to see. This season's Celtics team is deeper and better. If they can bottle up chemistry and consistency maybe they can get another crack at Miami and possibly exceed.