There's a reason a "prototypical" QB's size is around 6'4" and we saw the reasoning today. Troy's height resulted in a couple batted balls and it makes it difficult for him to stand in the pocket and find a target when there are guys towering over him.
I think he'll be a good QB, I'm just saying it would be easier for him to do his job if he wasn't so short. Luckily, he's mobile and puts his legs to use, which usually negates the height disadvantage.