Almost none of them come close to Allen's year, and the 10 or so you cite certainly don't constitute "a lot", if they even qualify. My point is just that very few QB's in the history of the NFL have a season the caliber of Allen's and then don't ever repeat something similar. His "one elite season" shouldn't be discounted so easily.13-3 is team success as is making it to the Championship success. Well if we're using your extremely specific criteria of 4500 yards 37 TD/10 int then not many if that's YOUR standard.
If we're using a more general standard yeah Scott Mitchell, Mark Rypien, RG3, Cam Newton, Derek Anderson, Nick Foles, Don Majkowski, Steve Beuerlein, Elvis Grbac.