The Steppe factions are definately some of the best suited to migration. I (Pahlava) wandered to the southern Baltic in an earlier build, and tried (and failed) something similar as the Saka recently - except with southern Gaul the intended target.

I've been trying to make a successful Swebo-Bastarnoz kingdom of late, to boot. Which I must say isn't going too well.

Really should stick with one campaign at a time.