Oh no Brady Quinn couldn't be super man in his first 12 NFL starts! Most QB's aren't that good in so few starts, especially when they have no help.
Here he isn't going to be asked to carry the team either. We are going to be a run first team who plays great defense. Quinn has the talent and arm to make throws that Cassel can't, thus being an improvement. Hes had plenty of time to sit back and learn more. Hes going to be a lot smarter and mechanically sound than he was three years ago. He might not of played in games, but he still practiced.
This is his first chance to develop as a QB. Start out as a game manager and add to his load more and more as time progresses assuming he can handle it.