From a simulation perspective, going down to county borders (Crusader Kings style) would probably be a feasible amount of granularity. Getting county maps and populations would be more time consuming than difficult, and county-level tax revenue figures might not be too much to add on top of this.
From a simulation perspective, going down to county borders (Crusader Kings style) would probably be a feasible amount of granularity. Getting county maps and populations would be more time consuming than difficult, and county-level tax revenue figures might not be too much to add on top of this.