Here is a very roughly done map which i think is some-what appropriate.
Now, in the final version I can see the Wesern Lobe becoming larger and more expansive, and perhaps shrinking the easern lobe just a tad,but all-in-all I like what I see. In respective Hidden Mountain ranges on the southern end of the Eastern continent you have the Sidar and the Mazatl. The Mazatl are completely surrounded by mountains, a few mountain passes as well as underground tunnels, yet almost all non-saurian creatures, sentient or not, usually die within weeks (one week?) of entering the Valley. Especially Mammals!! The Sidar, however, are far less hidden/surrounded ... its simply that the path to the Sidar lands is constantly covered in Storms and Mists. Also thick forests, and treacherous cliffs dot the landscape entering the Valleys of the Sidar ... so invading armies beware.
North of the Sidar is a great Streching Desert (well, technically north of the Thick forests and treacherous mountains which are north of the Sidar) which goes nearly across the continent as a great wide band of Sand and Scrub-brush, with perhaps a few cacti and some plains thrown in, and of course the occasional Oasis. This is where the Elohim, Calabim, and Malakim live, and shortly to the West is the beginning of a Meager Khazad empire. Far, far to the East is a band of Nomadic Shieam armageddonites just beginning to found cities some hundreds of miles north of the mountain range separating them quite irrevocably from the Mazatl. North still of this great strech of desert and its Emerging Powers are the Ancient Races of the Alphar awakening from their slumber. Scattered among the great Umber Woods, millions of Elves are gathering like the coming storm ... waiting to once again commence the brutal bloodshed.
On the Western Continent is basically everyone else, although I suppose the Nortek could find themselves wandering across the desert, or the plains between the Desert and the Umber Woods. Or any other nomadic-type civilization who is thrown in there. I figured the Infernals would probably be summoned onto the Eastern Continent, or somewhere completely different even, and the Mercurians well, thats another story.
The Western continent, starting from the East, is the great Lands of the Orcish, with the Illians to the Far north and the Doviello to the NorthWest. To the South of the Orcs are the warring States of the Hippus and the Khazad, while to the West of the Clan are the expansive ruins of the Bannor. West of the Hippus are the Kuriotates, and beyond them the Grigori and the Dural. North of the Grigori, or West of the Bannor, are the AMurites, Khadi, Cualli, and Lanun. The Lanun are on the Western Coast, while the Amurites and Khadi are next to each other like the Grigori and Dural are, only more northward. Even more north is the Cualli in their Northern Marshes.
West of the Grigori are the Balseraphs, Gnomle (probably), and distant Lanun colonies. (in the southern Islands, roughly south/southEast of the Balseraphs, is a collection of Balseraph and Lanun Cities on a dense archipelago) Somewhere among here are the Cliffs of Hastur. You could go farther West still to include any other civs ... most likely of which being the Luchuirp, however the Luchuirp are probably closer to the Amurites, Illians, and Bannor. However, an emergent and nomadic Luchuirp Clan could certainly be first spotted/established West of the Balseraphs. Anyways ... the Nation Density on the western Continent is much moreso than the Eastern Continent, the East is supposed to have more wildlands, and also be home to the more reclusive civs, so to speak.
For instance, the lands referred to as bannor, khazad, hippus, kurios, amurides, khadi, lanun, grigori, dural, and balseraphs could easily fit many more nations as it is the most "civilized" region of Erebus. And by civilized I mean the most Trade/Merchant based, with the most open borders and free cultural diffusion, generally the more "western/modern" stereotypes enter here, but all it means is Open Borders and Cultural diffusion.