I believe we should distinguish mountain, woodland, and badland regions more, instead of lumping them together as "other".
Mountain regions should have much higher gold income but much lower food production than an rural region. They should be net food importers like cities. Currently it seems that most mountain regions can feed themselves. If realm A wrecks realm B's food supply chain, realm B shouldn't be able to keep its gold mines, iron mines, and stone quarries operational.
Woodland regions should be somewhere in between an rural region and a mountain region in terms of income and food production.
Badland regions should have much lower food production and population than an rural region, especially if the region looks like a desert or a tundra on the map. You could argue that they still generate some income from trading and crafting. Dwilight is pretty good at making this distinction, but on the other maps, a badland region is not that different from an rural region.