They do that all the time, and if you dont have the regneration spell on its gameover. Thats basically the only trick to know to defeat any boss so far , regen on, the druid get one shot, next round regeneration make her go up,place a few attacks taunt or not doesnt matters, an AOE attack will likely take down your squishy characters, refresh the regen or again its game over. Rince and reapeat until the bloated hp boss dies or you run out of potions .If you are unlocky and healer is paralyzed , reload. The word tacticool is indeed fitting.
As for the ambushes , dragon age 2 enemies falling from the sky , ambushing you was an horror , but here its completely accepatable as its a turn based blobber...