I think Hank was an effective hero, but not necessarily a good leader. Yes, they took down a lot of very high end powerful bad guys (with Hank himself often doing the lions share of the heavy lifting). But he also got his entire team to quit because they essentially thought he was nuts.
Part of me wishes Loki had taken Hank up on his offer. With the rest of the team quitting, Mighty Avengers could have essentially been a Hank Pym/Loki buddy book.