Obsidian is more efficient to holding its self sharper than steel, but not in a wooden club. and yes Katana is most Sharpen Sword.Mayan destroy their World them self, only few Cities surviving, that called Mayan Collapse. im i agree with you with Aztec weapon is no made for figthing against a European Armor, but Cortes forces was small comparated with Aztec force, Tenochtitlan was one of the largest in the world; compared to Europe, only Paris, Venice and Constantinople were larger.