Something to note... the issue still comes in that the average magisters among other races are still miles ahead of the average human version in the field. While there ARE more special and unique mages that happen to be human, they are woefully NOT the norm. Also Jaina was hyped up on villain arc energy and was made to be far above and beyond everyone.
And it's still hilarious to argue that Zandalari are second hand learners.... cause so are humans. Mind you that the same magisters among humans can include those who have also transitioned into undeath and kept their knowledge and mental faculties (and lost a lot of safety limiters because... reasons....).
Basically, Allaince still has some of the Shendralar and a few high elves to accompany the human magisters....
But the horde still has 2 nations that are almost exclusively run by magister favoring denizens and a smattering of other magically gifted groups extra that also includes some with humanities affinities still present despite their physical/mental conditions.
Using the hero tier as proof kind of falls into a certain other problem.