"It's interesting how CA thinks blunt objects like hammers and maces are armor piercing."

Well actually bashing someone in plate armour with a big spike on a big weight at the end of a big pole was much more effective than trying to stab or slash at them with a sword. If you look at the war hammer in question you will notice it has such a spike. Also, even a large blunt weight alone was more likely to collapse armour, or concuss the wearer, or knock them over. There is nothing at all wrong with making weapons like hammers and maces more effective against armour. They were largely used for that reason.