Well, when the Akatsuki took out the Jinchuriki, it was 2-on-one fights, and now it's 12-on-12, sort of. Including the 6 Paths of Pein, it's 12-on-18, add the other Zetsu (you have him once, even though there are two of him), it's 12-on-19, and add the thousands of Zetsu clones (which Naruto's been shown to take out easily), and it's 12-on-uncountable. But, seeing as they have four Kyuubi jinchuriki's (three psuedo, but still) that are able to utilize their powers together to destroy, and with all the other jinchuriki covering each other's backs, I'd have to go with Jinchuriki (mainly because Naruto himself has basically killed 7 + a LOT of Zetsu's himself, and there are other OP Jinchuriki to help the rest of the Jinchuriki out, as they were all fighting on their own against two Akatsuki beforehand).