I think we are on the same page overall in what goes into throwing the football. The point I was trying to make is that on the margin, weight room work won't make that much of a difference since very few QBs have perfect mechanics. Improving the mechanics will have more impact someone like Peterman compared to having him lift more weights whether it is for his lower body , torso, or arms. Optimum timing of when each muscle/ body part is activated when throwing is a lot more key then having bigger muscles.
Is there an QB in the NFL that substantially upped his game to another level because he spent many many hours bulking up in the weight room? Unless some high prospect had the muscle tone of Urkel, I don't think many NFL QBs have a need to go beyond regular conditioning regimens?