Considering two franchise QBs (Rodgers and Matt Hasselbeck) came from schools that you so easily dismiss, you might want to rethink your assumptions. And since when is the Big 12 not a good conference? And big Ben is ahrdly the only small school QB who has had success. Steve McNair came from Alcorn State. So, I don;t think there is any correlation between what school you went to or what conference you played in as to your readiness to play right away.
Texas A&M's schedule last year consisted of: Oklahoma Oklahoma State Texas Arkansas Texas Tech Kansas State Missouri Baylor That's about as hard of schedule outside of an SEC team that you can get.