The question is framed in terms of the bottom of the playoff spots where the Celtics are. A better way to pose the question is in terms of the top spots:
Heat. Knicks, Pacers vs. Spurs, Thunder, Clippers
I'd say that's pretty close, but give it to the East due to Miami. Then the next tier is:
Nets, Bulls, Hawks vs. Grizzlies, Nuggets, Warriors
The West has the edge there.