I'm not sure, but I think almost every block is taken up for weapons, all of them maybe, and I came up with a possible way to add more weapons than blocks (when we do have more) or just switch a weapon to a different block (IDK why you would, just because it's your favorite color?). You could make a command such as /blockset [block] [item] and that item would be switched to the block you want, the other will be stored somewhere. Just another suggestion, you should make it so you can only take 2 weapons into battle, adding a bit more strategy to which weapons you use. Maybe another command such as /weaponset or /wset [Weapon 1] [Weapon 2].