That was something that we came across during our run with the combat mechanic. We ended up modelling few ruins (for our dark magic evil robots) and spaceship wreckage (for your friendly survivors) that will spawn in the map follow by a few predetermined rules, so it’s something that is going to look like this:
For the sake of AI and navmesh, these ruins are probably not going to have as much randomness as the terrain, but their placements will be random with a few exceptions, like a highly guarded area at the center for example. Still a lot of fixes needed though, we are always trying to find the right balance between randomness and fun!