Before I jump on the "bench Arch" bandwagon, I'll throw this out. He looks like a first year starter who has had very few meaningful snaps. When you're the backup QB, you can play loose and fling the ball around without much pressure if you know you can't be QB1.
But when you are QB1, there is some pressure. You can lose QB1 status. When you are the pre-season favorite to win the Heisman, that could add a little more pressure. When your last name is Manning, there is a whole heck of a lot of pressure. Has any Manning QB been benched?
I believe the expectations for Arch were a little high. He needs to play loose and have fun. Forget QB1 or QB2 and just play like he knows how to play. It'll come. It just may not be this year.