If you drafted Peyton that was obviously a risk you were willing to take.
Best case: Peyton goes off and the Steelers ST bails you out, while Ryan can't take the noise of Arrowhead and melts.
Medium case: Peyton doesn't play great but PITs D makes up for it.
Worst case: James Harrison rips Peyton's head off, his backup shreds the Steelers weak secondary, and Ryan had a career game.