True, but what if he becomes a member at some point?
But yeah, I wouldn't worry about it right now. Sir James already has a gonfalon painted up, etc. If the other dude were to join us, I'd just try to recommend adding a point of difference to one or the other (like a border or something).
This is why I registered mine in the SCA, so at least the big juggernaut of medieval heraldry in the US has my uniqueness preserved.