What happens when two (or more) players both build rockets to propel the same asteroid (or moon, or planet) ? I'm sort of imagining this comical game of tug o war with two different people trying to control the flight of the same asteroid, both having rockets on it, both trying to crash it into the other guy, but neither actually having full control of it because both have rockets built on the surface. I find the idea of artificial rules stopping you from trying this somewhat repulsive. Just because the other guy happens to be on my planet shouldn't prevent me from building rockets on it. Just because I'm building rockets shouldn't prevent him from building them too. Let it be a race to control the fate of this big ball of rock. I think it could epic. Or maybe it would be a terrible idea. You decide.
I guess in such situations the easiest way is to just overrun the enemey on the same planet with tanks (you have more since he used his ressources to build rockets) and then do whatever But I don't see why it should not be possible for more than one player to tamper with the orbit of a planet/asteroid/moon. This may even become a new game mode like Phantom or ZoneControl was for SupCom because it sounds kind of fun. "Planet Racing"