The reality is that our coaching staff's ability to screw up QBs is rivaled only by their inability to come up with an offensive game plan. Johnny Manziel would look like a 'one or possibly two star star division one quarterback' if Rhoads and Mess were coaching him.
I think this is as close to reality as anything, unfortunately. It doesn't matter who we have under center in this system. Things are so screwed up, poorly taught, and mismanaged on gameday and during the week that we could have Johnny Manziel and it wouldn't make much difference. We've seen this for several years now, and it's not going to change until major upgrades occur on the offensive side of the ball with those wearing the headsets.