I see the solution here: they're 8 of them, they're in that stack, and have superhuman abilities. you can use them to single-handidly bash the grey death, then expand south. as for the steppes: live with it. trying to mount an attack on them is suicidal: huge distances, little to no roads, and lots of HA's hell bent on making an invader's life a living hell. the only ones who can properly tackle them are the phlavan, the Saka, and other sauromatae (though there is only one)