* The metropole (most populous and powerful areas) in your world are going to be the most fertile and resource rich regions that have good communication throughout, whether by the use of rivers or the use of roads. These areas are likely to have a much more stratified social structure based on class, as there will be more for the wealthy to siphon off to enrich themselves.
* More marginal areas, like Rho, are more likely to have more egalitarian societies, as they have to share between classes to survive. If they are very rugged and lack good communication, it is very unlikely that a centralized ruler will pop up (unless they are using magic or a new technology, like airships).