Easy fix would be to increase the detection abilities of the Hob Goblins AKA Vex Snipers and the Wire Rifle Vandals AKA Fallen Snipers. Keep their physical player detection range the same so that they don't sense you are there when you're already 1500ft away but make their detection fields sense bullets. This isn't unrealistic as a real person would hear the bullet fly past them and would see their friends die. The sniper enemies could then start taking cover to get a shot back on you but you should still be outside of any effective range of other guns... Good AI would make any normal enemy (not snipers) move more frantically trying to avoid a potential incoming round, or maybe even start taking cover based on direction of the shot... Maybe this is difficult to code into the game but that's why you're Bungie. The Developing company... figure it out. Don't take away a strategy/play style that isn't actual Cheesing (jumping onto the tower at the bridge in Crota's End to trick the game into thinking all active players are already on the ogre side).