I don't it matters what kind of offense they put in there.
Now that we've seen Keenum operating successfully from under center for a majority part of the game, we can say with confident that he's not a system QB.
Offenses can run the PA from under center or in shotgun, or in pistol, etc.
At any rate, here's a look at some more of Keenum's throws.
He does make the job of the O-linemen easier with his mobility, his quick decision making and release.
http://m.bleacherreport.com/articles/1836516-is-case-keenums-breakout-performance-a-sign-of-things-to-come
My comments didn't have anything to do with Keenum really. My point was that I think kubiak is really good at offense.