In my last playthrough I just struggled with 2 since one of the melee bugged out and got stuck on plotting next move forever, and the sage never came to Ethel's house and went to chill on the swamp.
They are very easily cheesed with burst damage, though, you can heat weapon with druid on one of the melees and frightening strike with Lazael the other one and cast Hold with Shadowheart on the third and just burn down one by one.
