I'll agree with to others in dealing with body piles first, I've cleared six crypts so far, all in troll as upgraded as I can get it, with bronze sword and buckler (sword upgraded to iron after first two, buckler remains unchanged). The parry stagger helped me greatly in buying enough time to focus on the pile, but killed the mob if it's between me and the pile, and destroy it before another spawns.

Another note, I believe that they will only spawn as long as you are within a certain radius, so if more that two spawn or you get low health, run away several rooms if not out of the crypt. The enemies will follow you if you remain inside, but you can move to a better position to take them out without anymore joining in, then recover yourself as needed; before trying again the destroy the pile.