That might be all he needed... People point to Aaron Rodgers, but he was one of those system QB's that happened to be one of the few that had a pro skill set. Definitely took a couple years to get him on the up and up.
Harbaugh already had Luck running a pro system. He shouldn't need any more than a season, if that. And that's not to say he won't look bad if he goes to Indy and they still have crappy players around him next season.