Is there another RTS with procedurally generated terrain? I'm not sure what RTS you are looking for Ashes to be more like. The engine supports any level of detail (again: procedurally generate terrain). Which game do you want it to look more like?
I've actually given this issue a bit of thought with all the various posts on the subject- the sharpness of the models for units certainly makes them 'pop' when seen against the terrain, which is good, but it does sometimes make the terrain look a bit...dowdy?
Is it possible instead to add in slightly more variation on size/typing of things like trees and streams, and possibly make the coloration stand up/out a bit more? I don't want to see it become something hand drawn, of course, and I obviously don't want to either fail to instantly see units (like I do now) or devote too much CPU/GPU cycles to this, but it seems like a little more brighter colors and/or slightly sharper lines (emphasis on slightly) might be nice. It's not really a problem with the terrain itself, I love the slopes and hills, it's with the details, making them a little more visually interesting (emphasis on little) might make them not just 'noise' but pretty in their own right- it's really the hefty contrast between the crisp units and the sort of fuzzy dull trees that brings it to attention at all. Obviously don't go overboard with this, I just think there's slightly more middle ground where it might bring the background world and the units slightly more in sync with each other.
Just my thoughts.