re: What advantage, if any, is having rotating QBs

There are several obvious advantages.

1. If the most talented guy still isn't ready it allows him time to develop while you get the advantage of better QBing while the less talented, but ready, guy plays.

2. True freshman usually don't have the best grasp of the playbook and fundamentals. They get everything straight before the game, but as the game wears on they lose it. It helps to sit them on the bench for a series or two, so they can settle down.

3. Different skill sets force the opponent to spend valuable practice time preparing for each.