if we were to go geographically, the core province might look like this. This would be 6 tiles out NE, SE, SW, and NW. the tiles going N, S, E, W would only extend 5 away from the capital, keeping with the way all civ games trim the corners. from here, we could extend imaginary lines out NE, SE, and SW to further divide the territory into quadrant type provinces, and fudge the lines to accommodate outer city placement.