Creating and Efficiency 6 & Efficiency 8 enchantment

I'm trying to make it possible for a pickaxe to have either the Efficiency VI or VIII enchantment. However I don't want people to be able to just craft them by combining vanilla Efficicency V pickaxes to get there. I tried making two seperate enchantments and give them the exclusive set tags so that they are not allowed to be combined with vanilla efficiency. I'm now getting the error that it doesn't recognize my own exclusive set. Which I made to make sure non of my special enchantment can stay together.