I'm not sure I understand what your analogy is trying to point out here, perhaps I'm being a tad dense. If I'm being honest, the part I take exception to is the idea that if you are Anti-facist you are by definition a 'member' of antifa, which IS a group (however you want to splice it). I know many people from that group who do not speak for me, and have far more radical viewpoints than I do, therefore I don't want to be associated with them. I do not need to be a 'member' of a supposedly fictional group to also be anti-fascist. In the same way that you don't need to identify as a feminist (or slap a label on yourself) to be pro-womens rights. What I'm trying to say is that political labels/organizations rarely only represent what it says on the tin so to speak, Antifa does not solely represent anti-fascism (or at least not the people I've spoken to).