OK here goes:
We divide the map in little squares (20x20 for example)
Each member gets a random number assigned by WoT.
People choose there "realm" when it is their turn (their number) for however many units they want (max 10 for example)
When everyone is done picking, Wot will make it into a nice map with things that look like actual borders instead of a bunch of squares :-)
We then get to decide on mountains and what not for our OWN realm. If you and a neighbour have different landscapes in mind try and make it work somehow.
Would that work?