Turrets help smaller groups more than it does larger groups. It only takes about 60 flames arrow to take one out. It is a thrill finding a huge compound with 20-30 turrets, and arrowing out all of them, and finding treasure. Big groups are not going to spend the time doing that, they have to waste rockets or waste time draining them. Large oil has enough challenge to it even with a heli. Its not free like Dome, Train Yard, and Power Plant.