Actually, Eekiki, you want to look at raptors. Between tail swipes and fire breath you gotta be plenty careful about positioning and WS triggering around them. Also careful of spawns/adds because seriously, one of them spawns too close and goes unattended for a moment and BAM everyone dies D:

And I do agree with you, levelling parties should in fact require a bit more of strategy, without actually slowing down the parties.