I feel Havenstone probably needs to make a codex or wiki like Cata for all the lore. Shayard is actually an unholy mix of a Franco-British union. You’ll note the part where the mc hails from is more anglo-saxon, while the more affluent southern and coastal regions are more French inspired.
Here’s the guide to Shayard’s major ethnic and cultural divisions.
The other “provinces” of the Hegemony likely have their own divides too, but at the moment only Havenstone knows what they are.