I repeat the question: what should the total population be? I genuinely don't know, but I have a feeling that the presence of more than one or two big cities (we're talking 100,000 population) might be bad. Too hard to realistically conquer. On a side note, with a fairly fleshed out nomadic shaman tribe, and a vague storm-worship group we still need to come up with a few more nations. 

I for one like the idea of a nation ruled by tyrannical warlocks that make Shaige's magic look benevolent. Spurned and cast out by all the other tribes for their horrendous practices, the warlocks and their followers were forced to live in the shadow of a range of volcanic mountains, surviving in a volcanic wasteland. Some places are fertile from the volcanic ash and home to real settlements, but vast swathes of their hellish land are srained black from soot and ash and are house nothing save lawless men and death. However, this group has recently had a schism; the warlocks' absolute authority has been challenged by a new fervent cult that seemed to spring out of nowhere, claiming to have reached contact with a divine spirit named Caldor. 

Naturally, if I end up as one of those that control an NPC group, the one abve is what I'd like to do. A different mix, with both the cliche fire magic as well as evil warlock stuff, along with the opportunity for a clever Keeper to weaken the entire realm by manipulating the warlocks and cultists into fighting.

For other nations, we could have something similar to the ice witches north of Paterdomus that I only mentioned in passing. The idea was basically a kingdom of ice and death, with the ice witches actually being immortal demons from Kokytos in disguise. To reap souls as well as harden their mortal followers, the sadistic ice witches allow their magically-elongate winters to wreak havoc upon the human population. Disease and starvation lead to the weak dying and in some cases, the strog resorting to cannibalism. Hard places breed hard people though, and whenever given the opportunity the witches' followers will pillage enemy lands with a ruthlessnes and desperate fighting that can't be described, as their survival often depends on stealing from other lands.

Like these two nations?