Resources are actually capped, so how many you have doesn't really matter, the most important thing is the income. And income is just number of bases. And no, there's no routes for resources, it's a single global value. If you have wide borders, you'll use all your resources, basically. This is very obvious on "Himeji", where the empire outside the castle has more territory but the guy inside can hold because the choke-points mean neither side can use all their resources! (that's probably the hardest map because of it)
I do want to expand on the idea and have these as more tangible concepts, though. One idea I've being toying with is making it stateless (for performance/possible to run in parallel), so resources would be like another thing inherent/spread on the map, and that could influence how an empire grows and fights and the costs of those things (like fighting far away from a base would cost more than fighting near it, but obviously this would be a massive balance change).
Thanks for playing!