Shayard’s major regions have been mentioned in game, but not systematically. They’re the Rim (far West), the Westriding (central West), the Southriding (southern plains and coast), the Coast (eastern Coast to Erezza), and the Reach (north, bordering Karagon).
The former two have an Anglo-Saxon inflected culture, the third and fourth a Franco-Norman one; and the Reach is an odd blend, the crucible of Angelic religion, more culturally Karagond than any other part of Shayard.
Within those regions, there are large districts. For example, in the Rim you’ve got the Outer Rim, Norther Rim, Rimhert and Rim Hethe, and probably a couple more I haven’t pinned down yet. 
Edit: in the Coast and Southriding, the peasantry also have French names. And many of the Westriding and Rim nobility consider themselves culturally different from the south/coast.