Hey Doug, Scott(Friend) hit this one on the head. If the arrow flies well, the broadhead is sharp and the shot is on the mark, you will be a happy camper.
With a given set of wood arrows, you really don't have alot of control over FOC like you do with carbon arrows. At a given arrow weight and spine, carbon arrows will almost always have higher FOC just because the shaft is lighter.
The truth (my opinion) about FOC is this: you need some FOC, and all arrows have it. it's typically 8-12% or something like that. I think that the UFOC, EUFOC, ohmygod%^&@%^#%FOC, is a lot of nonsense. Maybe it makes things better .... maybe not. I think it's not worth worrying about. Does 93octane gas make your toyota tercel run better? Who cares if it runs fine on 87.
More than 10gpp is no problem, your arrow won't be quite as fast and flat shooting but the deer wont mind.
Shoot more, philosophize less .... thats my take on it. Good luck.