What*, didn't*, are*, are*. And no. You're being blind to the ability of the card that beat up Nightmares and Piranas.. What if the SoB clans were taken down by an 8 powered Soa ability? Wouldn't that give the same result as it's down to base stats, and the cards who were beaten were all 7 base power or less. Not that game logic is in any way applied in comics, but still.
My entire "thought" of this is that they're possibly adding "nega-clans", starting with all-stars first (the idea being that there would be an "opposite" of each clan, with their bonus being the stop version of said clan). The "masked warrior" is probably nega-el gringo.
Obviously not a Leader. And we can denote it's not from the 3 Clans shown.
My money is that there are multiple cards coming out, and I'm also betting that they are all from DIFFERENT clans.
Now, which clans hate Montana, Pirana, AND Nightmare?