Thatts because im not using ONLY this as a argument, you are, you are nitpicking, you ahve to see the whole picutre, everything.
You are dumbing down the classes to fit your narrative, "hey warlocks and DH both have control over demons, so they clearly are the same as blademasters and warrior who have mastery of blades, therefore, blademaster and warriors are different classes because warlocks and DH are different.''
You are using a fallacy, plain and simple, not just one, youa re going to false equivalence, to circular logic, affirming consequent and many others, which is pointless to discuss any firther knowing you will bend and disrtor anything to fit your idea.