Thanks for the input so far
What about this:
Early age: Draconians and Dragons are only present in full glory.
Middle age age: Draconians are still there, but the dragons are dying/instinct/becomming rare race. The introduction of human servants/worshippers/slaves.
Late age: No dragons (besides the pretender if you choose a dragon as prender that is). Only a few Draconians left. The humans build a cult about the Dragons and Draconians (like Dragon Knights and something like that style). The introduction of earth magic path and a mechanic steam dragon build by humans.
I think that would fit nicely into Dom3 world if you see how the other nations evolve.