Dragons of the world of Ashan.

I'm all for dragon-mania, meaning dragons should rule the worlds and occupy the corresponding position in the unit hierarchy.

That's exactly what it is. Servants of the gods - level 7.
But there are no servants for mages/necromancers. And not for demons either, because there's anarchy there, and the god is lurking in the depths of Shio.

Their pantheon isn't as vast as the many gods in Greece or Rome, but there should be 4-5 supreme dragons. However, they themselves don't descend to earth; they can take on a physical form, but their spirit is indestructible.

Well, that's what deities are. Like in ancient Greece. Everything originated from Chaos and Order. And a large number of gods isn't necessary. Because each race has its own god. And many gods mean many races. And many races mean many add-ons.:D