This goes for all domain-based games, both PbeM and PnP:

In Anuire you have what is essentially a '3D' lattice of domains, with overlapping temple/guilds/mages to make it even more interconnected. Physical obstacles are relatively few, terrain is cleat and there is little in the way of massive Awnie realms blocking movement.

Elsewhere (Rjurik, Brechtür, Vosgaard and Khinasi) this is not the case. Oh, there are some exception, of course, but largely the setup in clearly more '2D' - i.e. just look at the string of Rjurik realms, or the string of Brecht realms etc., cut of from other playable realms by massive physical barriers or awnie/nonhuman lands.

This really doesn't add much to the game experience IMO and this might be part of the reason why Anuire is heavily favored when it comes to domain games.

Can anything be done to remedy this? I'm looking for ideas here...

Personally I've had success with the area centered on Rohrmarch before...but to make the area truly interesting you must set it us so that it's possible to interact with such places as Massenmarch, Kiergard, the Chimaeron etc.