It is my experience that when these discussions get down to precise definitions and simple pedantry,pedantic, have forgotten the real value of the discussion. I don't think it is important whether a gnoll leader is a 3rd level fighter, or if they fight like a 3rd level fighter. It's not important. The important part is whether the GM is obligated in some way to build that NPC with the same rules as PCs, and whether a thing that NPC can do should be necessarily available to a PC who desires access to it.