I don't. There are no scarce resources in the game. Even if there were that is where diplomatic comes to play. I've played Atitd ( it do have very rare resources), player were able to set up buildings and monopolize them. It made the diplomatic and political metagame much more interesting. Problems can not only be solved by force.If you are able to wipe out another tribe just because you don't like they have a resource you don't, that would kill every small tribe in game and would only encourage huge zerg tribes. Xsyon would become an empty world very soon.