Юниты "Might & Magic Heroes VI"

Why was it ignored, after all, the events take place 400 years ago?

500 years later.

Who knows who lived with the elves back then.

The elves are still a united people.

And wizards also had beastmen living with them.

Exactly, the Elven Tribunal (T.E.) didn't exist yet, and the Faceless Ones hadn't been exterminated yet.