I've finished the game with my monk on Normal before the patch, so Edér was tanking almost everything and I generated very little wounds in most fights.
However, by far and large my monk was the MVP of any fight that I was outnumbered - any fight I couldn't flank or generally debuff enemies so my rogue couldn't sneak attack with ease, my monk shined - and if anything slipped past Edér he was there to tank it and get some wounds going.
Of course, towards the end my rogue adventurer catched up to my monk PC due to sneak attack bonuses. Patch upped the damage a bit though so I'm not sure if it'll still happen.