On PC graal, not sure which server, there used to be GvG. That seems like a lot of fun, and I think it was 4-5 teams of 25 players making it a 100-125 pk fest. Not sure if they could make a bigger arena than Dozer's War Room, but if staff could they should make one with walls, a queue button, grassy land, and spawns that create a circle for each guild.