Let me help you about M'uru Phase one did spawn some"npc's" as you just wrote them off as simple. They were anything but, they came quickly, they came on a timer, and they came in waves of 6 three per each side of the room two
Shadowsword Berserkers and one
Shadowsword Fury Mage per side. You then needed one tank to pick up the two berserkers which hit incredibly hard and another tank to tank the fury mages, the trick was that when the berserkers would
Flurry the tank would almost immediately become unhealable, and the fury mage would cast
Spell Fury Which would need to be spellstolen or interrupted constantly or the tank on them would also die. These adds needed to die quickly as the next wave would start counting down the second the first arrived. If a dps player pulled agro on an add they died, if a tank couldn't pick up an add in time they died, if the
Void Sentinels were not tanked correctly you wiped.
This is just phase one mind you, so saying "it was just set up that if your DPS was sleeping, things became problematic" is far from accurate. Dps had to be interrupting dealing maximum dps misdirecting constantly stunning for the tanks, debuffing mobs for the tanks, and staying aware. As a rogue on that fight I felt pretty crucial to the survival of phase 1 and pretty much had to pull out all the stops to help the tanks around me and the other dps. It's not something you can read about, you would have had to be there and before the fight was nerfed.