The Philosophy of Heroes of Might and Magic.

Why do you think so?

Many planets are similar to Earth. Although it is possible that their ecosystems have been altered. And this galaxy also has spiral arms (see the good ending of Might and Magic 7).

not for the amusement of the Ancients
they were created by the Ancients to develop and evolve

Uh-huh.

(in which it almost died out due to the war between the Ancients and the Creators).

Well, not exactly a war. It was a universal power struggle. It is quite possible that the Great Elemental War mentioned in Might and Magic 3 was part of it. The Creators (there are also alternative translations: Progenitors, Builders, etc.) most likely created the Krigans - demons.

Added 2 minutes ago

Christian is her subject, and therefore lower than her on the social ladder.

Christian is not a subject of Catherine, but of Roland. That is, he is an Enrotean, not an Erathian, and is a subject of Catherine only as the queen of Enroth.

Added 1 minute ago

It is simply impossible to classify the societies of necromancers and elves (for example) as belonging to the same group.

It is possible. As a group of civilizations created by the Ancients.