New class - I feel like something's missing.

[Maroon]

So please, don't try to say that NI is realistic.

There a difference between no fantasy and realism. Yes, being able to fight a Norse god is beyond realism, but to add a magician would throw it way further in the fantasy section.
And you don't need proof for everything, simple reasoning can tell you the game will change a lot if you were to add magicians, just like it would if cav would come back, because the entire balance of the classes, Nords, weapons and armor would need to be redone.