Duplicated Armor Drop Glitch

I'm trying to make an entity in which it copies the armor, main hand, and offhand of the player. Everything works fine, it copies the armor and main hand, but when it dies it drops the items it copied and replaces the player's items with the items it dropped. I have tried using loot tables and deleting entities inventory before it dies, but nothing seems to work. If anybody can help that would be great!