I don't think that is Lawson's problem at all, I believe he is just not a very aggressive guy. If you look through his history with the Nuggets that has been his 2 previous head coaches complaint and if you even go back to his college days he would do the same type of stuff. That is one reason he will never be a true leader on the team, and that is always going to be his big problem in taking the next tep to be the all star type that he has the physical talent to be.
I think that his psychological makeup is just too hard to define unless you know the guy really well.
The fact is that, playing for Karl, Lawson did have identifiable series of games where he was more aggressive and took it to the hole successfully with regularity. Unfortunately, those periods could run anywhere for 5-10 or, at best, 15-25 games and then he would revert to a much more passive style.
Once Shaw took over, the aggressive periods became less and less frequent. In reality, with the right coach, Lawson could easily be a top 10-15 PG, averaging a productive 16 PPG and 9-10 APG but, of course always a defensive liability and, as you say, not a team leader.
That said, a guy like Chandler, even if he could remain completely healthy, also has the personality to defer far too often, offensively and Gallo has some of that as well.