Given that the battlefield is based on card building floors, it might be fun to have them separate, perhaps with Colonial Marines vs WY Mercs outside and Xenos waiting inside the buildings.Maybe you could set it during a nighttime rainstorm so that the shooting range would be farely low., I guess there would be nothing wrong with using other wargame buildings, depending on the scale if the minis, I hope they're 28mm scale, cos that's all I've got at the moment.