Avoidance is usually best when you're without in the weapon department, namely freezing or high to-hit/damage modifiers.
If you're already paralyzing them, leave them be (unless you accidentally paralyze them in front of a needed passageway/doorway/stairs).
Additionally, you may find that stealth's the word in the lower levels, accomplished via ring, appropriate armor, or ......
Monsters are typically sleeping upon entering a room in the lower levels.... keep them that way.