Separate all your companions and yourself. They cannot do spread damage if you are all separated on the field. You may lose a turn of moves but at least you won't lose someone on the first turn! Proceed to kill off one by one. If you leave 3 or 4 alive for a few turns you are a goner.
Satyr's are easy, just spread out your companions to avoid radius damage and just pick them off one by one. Now for Witch doctors I am afraid you are probably going to have a hard time so I suggest you try to just buff your companions and use other abilities besides witch doctor spells.