I've seen a one star fuling berserker that was already badly hurt (about a third of its health left) absolutely wiping the floor with a regular troll at full health. The troll had no chance, even though it did inflict a bit of damage so the fuling berserker was down to a quarter health.

Only've seen one two star troll so far (and I made the f... sure to stay away from it), these seem to be extremely rare.

Good catch! :)