I see what you're saying. The redzone is a different animal, though, and teams run wildcat, or jumbo sets, or put in defensive players in crazy packages a lot in the redzone because of that. Tebow in 06 was a beast in the redzone, but Leak was better everywhere else. I know JT is way more complete than Tebow was as a QB, but it is still conceivable that JT is better in the redzone, and Cardale is better everywhere else. if Braxton had a healthy shoulder, I think he would be used the majority of the time as the redzone qb (would we still call it a wildcat if he could pass?) If that were the case, I don't think people would be demanding Braxton be the starter, they'd just recognize that his running ability is more useful around the goal line than having a rocket arm. I feel the same way about JT playing there.
But you're right, the FANS may not handle it well. There were probably some Gator fans who couldn't wait for Leak to graduate too.