We had about 30 CoA geared toons (5-6 bots)..no warriors. Packed raid force back in corner and tanks/OT up front as a wall for we had no idea what was to happen. Triggered event and alot of mobs spawned 20 about? All hell breaks loose. Seems some are permarooted (archers. The archers I know summon so I assume others do too. I checked track and saw no named but chaos so I could be wrong. After a few kills and many battle rezzes I checked again and saw "The Bait" on track with us. I changed targets to him and we killed it, then Chief Ugruk popped. Raid force focused on him (alot of HP's) while OT group handled the left over spawned mobs. Killed the named then the mobile mobes then all the archers. I noticed no AE's. No idea if anything is related but we will try again. Thats how it went down for us. Chief dropped the belt.