I don't think we would've won even if we had AB, but here's an interesting thought:
A lot of times, Doc had Pierce guard Wade so that Wade had to deal with a bigger body. Plus, we double-teamed him a lot, forcing LeBron to do much of the Heat's scoring as well as playmaking. This proved to be successful for five games, until Bosh came back and we had to deal with three stars, not two. It should also be noted that Pierce exhausted himself doing this, as he had to guard the greatest player on the planet, too.
If we had AB, that allows us to put SINGLE coverage on Wade (who was not himself due to injury). That's massive, because it allows Pierce to expend all his defensive energy on LeBron, plus it gives us a great offensive weapon in Ray off the bench.
Again, I still don't think we would've won the series, but having Bradley would've helped a ton.