Even in college, Vick was a single read maybe two then run guy. His default is to run, not pass which doesn't make a good Qb at the next level where everyone is fast and big. Same with Vince Young.
Denard's default, to the lament of some, is to remain a Qb and pass the ball after his reads. This lead to him trying to force the ball at times instead of making an easy run. I think that he will only benefit from having a OC that actually is pass oriented.