Except we already had zandalari paladins back in MoP who used paladin-like abilities, which reinforced the idea they're paladins, and not "shamans/witchdoctors/shadow hunters". Not to mention that shamans, witch doctors and shadow hunters are not depicted by wearing heavy armor, shields and swords, and using paladin-like abilities.
It's not a stretch. That is basically the extent of what you claimed, considering shamans, witchdoctors and shadow hunters in nothing are related to prelates, other than all of them being troll-related.
Except you really did just that:
Except your interpretation is not really a valid one. What you said like saying "passing through a door" is the same thing as "passing by a door".
Except, no, they do not. As far as I know, Nathanos is the sole example of that, and on top of that, through Nathanos'
entire existence he did not use pets. Only when he became a "raid boss" that he was given two pets, which further supports the idea that he's the exception, not the norm. Just like Anduin wearing plate does not mean priests can use plate armor. Or that Garrosh drinking in Y'shaarj's blood means warriors can use shadow abilities.
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Except we do have evidence of Sylvanas apparently being able to alter someone's will,
back in Cataclysm and then again in Battle for Azeroth when she stated her plans for
Derek Proudmoore.
But they are intrinsically linked, kind of like hunters and dark rangers.
If you dismiss everything in the lore that explains how they're different, of course it's easy to say "there's absolutely nothing in the lore".
Because you repeatedly hand-wave them away. Address them and we can move on to different things.