I honestly think that hostile survivors would be a great addition to the game. It would not only make the game more interesting but also more challenging. The survivors would carry guns and be out scavenging, they could also try to raid your base but also raid your neighbors too. When you kill the survivors they would drop rucksacks of random materials (Ammo, Fuel, Food, Etc.) The survivors can be found in groups of 1-3 survivors each of which are carrying either melee weapons or guns. The hostile survivors could surrender but you have a choice, you could let them, A-Let them join you. B-Kill them, or C-let them go. A- will add more survivors to switch to, but you would also have more mouths to feed which means more scavenging, and a higher risk of being killed. B- You can kill the survivors/bandits and loot their rucksacks but killing them would cost influence and morale. C- You could let them go and in result gain some influence.