A sounds better to me. I agree about the splitting hairs thing.
Here, it is generally:
Recurve means any recurve OR longbow, and arrows out of any material. No sights or release of course, and no stabilizers.
Longbow means any longbow, and wood arrows only. Again, of course, no sights, etc.
So if you want to shoot carbons or alums out of your longbow, you can, but you have to register in the "recurve" class.
As for primitive, I've only ever been to one shoot that had primitive for a class, and I don't know what the requirements were, but I figured my take-down pronghorn wouldn't fit! :p To me, that makes me think self bow, or maybe a laminate but with little or no rest, and wood arrows only.