So... while each of the regions has a primary city (Achelb, Ellenici, Grisia, Kyran, Il'sha-ah, Imba, Musarra, Neasc) They're not "Capital" Cities. We're going this old(est) school and making every most cities into their own city-states.
Il'sha-ah will be an exception with it's Phaoris ruling over both the Head and the Body, twin kingdoms along the Cobra's length.
Kyran will also be an exception because the Kyrani are not city-builders, they're travelers.
The rest will just be the Largest and/or most Prominent city-states within their region. Near to Musarra, for example, will be several rival city-states along the flood-plain of the river. Similarly, Achelb, City of Thieves, will have it's own rivals along the western river. And somewhere in the middle, between those states, will be a few other "Oasis Cities" where the Leaders control the flow of water as a means of controlling the populace.
Ellenici will have a dozen warring "Kingdoms" and probably one or two burgeoning Representative Republics, Neasc will be ruled by Princes who all claim connection to some higher authority that may or may not exist, meanwhile Imba's tribal council structure will be indicative of the way the people of the plains live: Mostly in family structures wherein the central figure is, if not family, treated as family.
So between Achelb and Musarra I've got three cities in mind.
Sepfar: An Oasis city with a predatory streak. They're raiders and slavers who try and control the region through violence. Most of their foodstuffs comes from the three oases controlled by the city's ruling class. Currently in a moderate drought, the Theocrat, Ashuro, is conducting ritual sacrifices to call down rain as the water level of the oases has dipped. The city's population of eligible sacrifices is moderately sized, but Ashuro has been sending raids for potential victims rather than putting his own people on the altar. But with fewer and fewer successful raids it is only a matter of time before Sepfari blood coats his blade.
Ondat: North of Musarra, Ondat is a smaller city-state along the river that I really need to name... Maybe Ur? Could be a neat nod to Sumeria. Anywho, the River Kingdom of Ondat is ruled by a Matriarchal structure and is currently dealing with Sepfari Raiding on the uptick as they go further out looking for people to sacrifice. Queen Adranene of Ondat is trying to build an army to strike at Sepfar, but many of the city's people have already fled to Musarra to avoid the raids, leaving Ondat woefully understaffed.
Lagan: South of Achelb, Burana is also fighting off Sepfari raids, but doing it very well thanks to a mercenary army hired from the Khufu sea. Sharrans, Achelbites, Ellenici, and Imba all protect the city of Lagan. But the cultural weight of these mercenary populations is taking it's toll on the city. And there's even rumors that when the Sepfari Threat is ended, the mercenaries intend to stay and potentially overthrow Potentate Tyar who has yet to learn his lesson and is hiring mercenaries to protect himself from that eventuality.
There'll likely also be countless encampments and villages throughout the region, many of which are fairly mobile and travel with herds of goats or other animals, ranging from the seasides in summer through the desert lands in the short winter months where the heat is more bearable.
Mostly I've been focusing on Achelb-Musarra, I admit it. Sumeria has it's fingers in my brain.
I also wanna do at least one or two Religious Sites in the region where people make pilgrimages for different religious purposes, and perhaps a few "Buried Kingdoms". But this is my starting material.
