I like a lot of this post.
Pettine will likely dial up some crazy overload blitzes, and the Bills o-line has had issues with protection on a schematic level. Allen, as we saw with his college film, also has issues correctly diagnosing pressure pre-snap. So if the Bills offense gets off-schedule or behind the sticks, look for Green Bay to attack.
Shotgun is one tool that could help Allen better see the field, and I've always been a fan of diverse, loaded backfield looks (the kind, coincidentally, that McCarthy likes to employ over the years), but I don't think there's a silver bullet (or golden ticket or whatever) that solves anything against an NFL defensive coordinator for longer than a quarter or two.
Would love to see Croom coming out of the backfield. His athleticism needs to be exploited.