No fucking shit. And if any first round QB would benefit from sitting behind Manning, why does it have to be the #1 overall? Drafting a guy #1 who will not play for three years at the earliest is kind of a waste of value. If any QB can sit behind Manning and benefit, why not trade back into the middle of the 1st and let Landry Jones or Matt Barkley fall into your lap while also picking up 3-4 other assets?
I am saying taking a QB for the future is a luxury pick, and you can't afford to take luxury picks if you have a team that is bad enough to be drafting #1 overall. The value of that pick would not be fully recouped if you are gonna sit the guy for 3-5 years. (And really Peyton could conceivably play for longer.) If you don't plan on playing the guy anyway, you are better off finding yourself a desperate trading partner and stockpiling assets.