The world is full of undersized OL who are athletic but don't get grabbed by bigger/better schools because they're too small to play OL at D1.

Part of the reason the 3-3-5 works at BYU is because it is easier to get a big group of guys who aren't quite good enough to be CB's, aren't quite big enough to be LB's, so they fit in great at Safety. That's the talent pool you're looking at as far as wings and RB's as well.

I'm not saying BYU SHOULD go to the option. But I don't believe they'd have trouble getting players who could run it successfully (assuming they have a coach who can coach them to run it successfully.)