I don't think a lack of aggression was his problem. When he played with the second unit or played with a bunch of the first-stringers, he was set up a lot in the post. I don't remember him turning down a lot of shots. I thought he was more of a black hole. I don't want to know what he thinks more aggression adds up to.
What I wished he did or could do was fit in by being a better passer. It never hurts to be a good passer and passing would allow him to fit in with the starting unit better. It's all a process of him being a better an-all around player and high level role player. Right now, he's a below-average defender, rebounder and passer. When he's not scoring, he does absolutely nothing out there and more so, hurts the team because of his deficiencies.