Guess it depends on group setups, I personally beat that fight on first try at the level I entered, it wasn't the last thing I did either so I wasn't at max level. My rogue killed the boss in one turn and I don't remember the adds being much of a problem, I think I teleported a couple together to aoe knockdown with my warrior probably. Soothing Cold with decent hydro levels is especially good for this type of fights, my buffing char goes first due to being wits char, and it regenerates like 200 a turn(probably was only 100 a turn back then or maybe less, but it's a good amount).
In general I haven't had an issue with a single fight other than trying one of the optional boss fight in act2 when it was 3 levels higher than me(pro tip, that's an absolutely terrible idea, died on first turn). Everything else I've easily won, I've only had to rez a character once so far(learned that apparently web doesn't prevent skills that move you if they're attack skills, so an enemy I thought was disabled just blinked on top of my mage then crit whirlwind). My setup is very strong though I'd say, it's not completely min max but it's pretty optimized and I abuse CC a lot. It's amazing how much stuff isn't immune to a lot of CC. Polymorph especially seems like it was slapped together after they balanced the game and has several skills that seem to break many encounters.