I'd be much more worried for Cardale if he chose to stay, versus declaring today. He has drummed up enough intrigue with this 3 game audtion and should pass all the physical tests with flying colors, that he will go no later than the 2nd round. That is guaranteed money, no matter what happens in his NFL career from there on.
If he comes back to school I think by rights he should have just a good of chance as any of the 3 to win the starting job, but something tells me he wouldn't, at least not permanently. He also risks injuries and more tape can actually show more weaknesses over time.
People need to understand his decision shouldn't entirely be about what's best for the OSU team or even his development as an individual player. It should primarily be about getting the most value out of his future profession, and I believe that is to go pro today.
I think the best thing for all 3 of our QBs (as individuals) is as follows:
Cardale goes pro and gets drafted in at least the 2nd round
J.T. becomes the starter and team leader again
Braxton stays at OSU and takes on a hybrid role in the offense, which features occasional direct snaps and passing attempts. And is also the regular backup QB. I have my doubts his shoulder will be fully ready to be the day 1 starter regardless of what anybody else does. It has to be really hard for him, but I just think the shoulder injury makes it that much more unlikely he can become an NFL QB in the future. I see nothing wrong in becoming something like the next Antwaan Randle-El in the league, but for some reason most athletic college QBs refuse to try anything else. We'll see.