What makes thing even more funnier, I was told that original Corse itself asked devs to have set initial rep towards GJ (and vice versa) to be neutral-unfriendly. I do not know what purpose it would be, but I had RP with one Corse (which was named Picard as well, so it turned out into rather awkward family meeting) and no single shot fired.
I believe Sirian Junkers and Gallic Junkers are rivals, because Taus are their turf. And both can attack themselves, if they want to, but their fight isn't forced and they may as well ignore each other.
