I think it's likely that Hardaway's presence bothered JJ since he has sent as much himself. I honestly believe the bigger factor is Marbury's departure. JJ and Shawn Marion are getting a lot more opportunities in the open court, and even in the half-court offense the movement and spacing is much, much better. There is obviously still room for improvement, but it is better.
I also think there's something to be said for success breeding confidence.
Before the trade the Phoenix Suns were 12-22, and they've gone 6-10 since then. And frankly I think it would be perfectly fair to throw out the first game or two after the trade.
Joe Mama