By Year Three of the Sex War, the female infantry "heavy" weapon was a compact cannon that could easily be handled by a single StarGirl, but it packed the kind of punch that only the bigger military starships had had before. The power of an individual cannon was such that it's unlikely that these four women ever fought side by side like this. Early StarGirl terraforming, lacking an effective matter-converter, did make extensive use of rayweapons to vaporise unwanted material and the cannon was ideal in that role, too, so these four are probably helping to remove some pre-war city-site for drastic re-development.