Banks didn't have the vision or instincts to decide on the drive what exactly to do with the ball. In fairness to Marcus, I think decisions on the fly like that; Who and how to kick the ball to, or to finish, are instinctive more than cerebral. People seemed to chalk Banks's flaws up to laziness, selfishness, or just plain stupidity. I didn't believe that.
West and Greene, aside from lacking speed, didn't have "it" either. West, to me, is a 2 guard in a point guards body. Hes a perfect fit along side Lebron. He was destined to wind up there.
Telfair was the closest thing to true point guard after Rondo, but couldn't finish at the rim or play D.
I don't think Doc had an epiphany about how to run the offense, but it has had more to do with personnel issues and Rondo's maturation.