Yeah, I don't know either, but I imagine humanoid NPCs could have a bit better AI than this monster thing as they would depend on guns the same as players. Besides, a decent sniper usually gets the first shot in (unless it's a small moving target), but what happens next is a different thing. The squad or company the NPC belonged to should proceed to hunt down the sniper with some kind of rudimentary but still potentially dangerous tactics. That's how it goes in games (excluding games where NPCs don't react when the man next to them is killed, but I'm sure GGO is not that bad).