If Mamertines are very very close then that means it must be Syrakousai, only thing left in Italy worthy of a faction! And someone else said it as well but without reaction so that must mean that there's even more reason to think it is in fact Syrakousai!

And a faction no one has guessed as of yet? Mmmm, then its probably not an very obvious one. Lugii, they were close of becoming a faction in EB1 right?