True, cannot really expect Balotelli to be rolemodel, even if he ages, then again, there have been plenty of cases where player in correct environment has sort of calmed down and found his place and turned his fortunes around.
Ben Arfa, Balotelli are the type of players who tend to well initially at a club but then go off the boil.
Ben Arfa is more than good enough for Barca though. It'd be someone other than Messi who can actually create chances and do something with the ball.
It would be someone other than Messi that would contribute nothing to the team off the ball.