My second group started the Whispering Cairn this evening. (I'm running two simultaneous AoW campaigns.)
This is also a group of six: a fighter, a cleric of Tritherion, a rogue, a bard, and a monk (all human); and a goblin rogue.
Like my first group, they had no problem with the wolves, even though I added an additional 9hp wolf.
They moved the sarcophagus to yellow, but did not go down the elevator yet, as my first group did.
They moved the sarcophagus to green, and out came the swarm and the mad slasher. Whereas my first group had alchemical weapons, and had no problems with this encounter, this group did not.
They killed the mad slasher pretty quickly, but the swarm knocked a total of four characters into the negatives. One of them was healed by the cleric during the fight, but when they finally killed the swarm, there were three unconscious PCs. One more round and there probably would have been one or more character deaths.
That's a really nasty encounter.