Hi!
Piercing values of ranged weapons is part of the values we tweak when working with the inter-weapon balance of the weapons. At different points of time there have been different takes on which kind of weapon/attack pierces what enemies, dependent on which state the enemy is in and by how much (Monsters being generally the thing that stops pretty much every kind of projectile/swing).
I do see the confusion that could arise in regards to the behaviour of ranged weapons and how they interact with corpses. Feedback is noted.
Thanks for the heads up on this.
Best regards,
Kasper - Game Designer