Mainly because the playcalling has changed so dramatically. I'm confident that Wilson, given the same playcalling would be just as successful, as Romney.
Heck, look at Hall's game vs USU and then compare it to his game vs USF. USU is arguably a better team than USF, but Hall was nothing less than amazing vs the Aggies.
Regardless, it sure is nice to have such great depth at QB. Romney is a gamer and we're lucky to have him.
My biggest concern is which guy is going to transfer, because all three are FBS QBs.