Orc chief is awesome vs monks. I think their tankiness depends upon their mana, and the horde chews it up pretty quick (even if the horde is dying, all those little mobs trigger avoid or whatever it is). You can out-heal their BS with blood (at least I did with Mundunugu) and then return to romp them.

With Varaez, I had trouble with a monk in my mid-game. But once I had hero/legacies with dagger/axe I could land my maledicts (fleeing to bandage when needed while STSF charged) then return with axes to pincer/disembowel.

Druids I imagine would do quite well, again because of servitors. The same could likely be said about a conjie - but I don't have enough experience with conjurer to say for sure.

Shaman can energy drain them, which makes them flee (unlikely to kill)

I guess the most important thing is, is to make them fight your way...hit and run with them. Intensify is coming, so if you notice a round where they aren't communing, or otherwise doing some BS to your weapons...flee...and let them chase you to re-engage. Rinse/repeat