Assuming we go with my plan, here is what the countryside around Greyhawk might look like:
click to embiggen
I somewhat followed the Welsh Piper's automated system, but I halved the amount of farmland in accordance with a post by Rob Conley I can't seem to find. I also fudged a bit so that I'd have to detail slightly fewer towns. The area on the Greyhawk side of the Nyr Dyv relies on farming feeholders rather than a manorial system. As such, It would have significantly fewer villages than the Furyondy side.
I'm not entirely happy with it, but I can't quite put my finger on why.