I would argue the spec identity is better on modern WoW. Maybe classes are now less important than specs but thats because specs are what define you as a character faaaaaar more than in vanilla. You still are able to use all of them (warrior is one click away for being a dps or a tank).
You could use actions, abilities, spells because you learned them, either from class progression sheet or buying from a class trainer (wow). Sure, there were class specific quests to obtain certain abilities (paladin/lock mounts, lock demons, etc) but overall criteria to use x ability was - buy it from trainer.
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In that case i can safely say it was influenced by Warhammer and not DND.
Savage orcs fighting human kingdoms - check.
Reclusive, living in a forest elfs - check.
Wise, magically powerfull elfs living in a wonderfull city - check.
Trolls who can regenerate - check.
Design of orcs - check.
Dwarfs offsprings worshiping fire demon - check.
I mean, similiarities are off the chart.
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Eh not good comparison - you can play wow for like couple hours, say it is not for you and move on with your live. Try that with any of the hard drugs. Or not. Dont do drugs :/