Braun was pretty equal, Miggy was better in 2011. Look at the stats. The only thing that he did better this year was HR and RBI, the latter of which came from having Austin Jackson on in front of him.
He had a better average, OBP, OPS, BB%, wRC+ and wOBA in 2011 than 2012.
And he didnt lead them to the WS. It's impossible for one player to lead a team. They added Prince and saw some improvements in the rotation, and saw a breakout from A Jax. Miggy took a small step back and they still won the WS.