The game's AI is utterly retarded. Remember how hard it was to kill a dragon with a party of six heroes in Baldur's Gate 2? Or what about a Demi-lich (instant imprisonment, maze, meteor swarm, gelugon summon!), Beholder (paralyzation etc.), or Mind Flayer (each hit = huge intelligence drain)?
Nothing that hardcore in this game. Don't even bother; it's trash.