Its not just plausible. Its the truth.
Think about this series of events as unbiased as possible:
1. Four quarterbacks are on the roster.
2. A new, young quarterback is recruited by a new coach.
3. Three of the quarterbacks leave.
-Why?
a)The new QB already proved himself to be far and away better. (Down 10 shots of the purple kool-aid to believe this)
b)They don't want to play for the new coach. (Drink 10 shots so that the question 'Why not?' never occurs to you and its easier to just call the players slackers)
c)The new quarterback is favored in an obviously unfair manner.(Drink 20 shots so you can ignore this and #4)
4. Two of the quarterbacks that left hint to the media that they didn't receive a fair shot.
5. One of the quarterbacks transfers to a new college that already has four quarterbacks.
The answer is right under your nose, kicking you in the junk.
Hell, the former players said the damn answer themselves.