If Smith isn't motivated after 9 seasons in the NBA and nearly being out of the league all together nothing will. Watching the Mavs @ Spurs game George Karl was asked about Smith and he (sugar coating it) called him immature. He coached him for much of his time in the NBA. Green is a far superior defender and shooter.
Smith needs the ball to score. Its a completely different mentality from having the ball in ones hand to waiting on the wing for someone to pass to. I don't think he would be better than Green was.
Green is one of the 5 most accurate (active) 3pt in the NBA for his career. He shot 43% (nearly 10 percent better than the league average) and made 177 3's (7th in the NBA). He was big reason why the Parker-Green-Leonard-Splitter-Duncan lineups worked so well.
Smith is a volume shooter and continues to make mistakes on and off the court.

. You guys can't be serious.

