Gah, I discovered these bastards today... Not easy to deal with, but apparently I got lucky because I could siege on turn 2 after beating one such stack, then assault. But one was already spawned by the time I got the settlement, and he's still there. I have no idea how to deal with the guy, as he seems to have an even more dangerous army this time (not to mention he's camping in a very good defensive spot unlike last time when I could meet him downhill). Doesn't help that my Casse FMs like to get stuck inside forests, only to get killed by enemy infantry...