The quest somewhat fails on the "stealth" part but the all out warfare of it is certainly a good laugh.
Ideally if you really wanted the stealth thing to work i suppose the players should infact be stealthed and only decloak when revealed by NPCs, this would certainly stop the players camping the non flagged guys, ofc i have no idea if thats remotely possible to code or not tho.
And frankly i think alot of ppl will just settle for all out war anyway
