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In reality, I'm only confused by the Rocs, because the birds are actually called Simurghs and were taken from Heroes 7. Rocs in myths should be the color of rock and indistinguishable from them. Arab sailors described them as flying mountains. Simurghs, on the other hand, were with the Persians and were considered astral beings, unlike Rocs.
Secondly, the essence is more important than the appearance: the Gamayun is a prophetic bird that conveys messages to the gods. Isn't that the purpose of a magical bird? Although I don't know the lore of your birds.
I found Gweihira in the Berserk card game. There, it was a giant reptilian bird.
Storm Birds because of a more accurate translation.
There is also the Anqa - a giant evil bird created by Allah.
I have no complaints about the Rocs because there is a blue Roc in Heroes 6 (it was strangely called a Roch there).
I think this: there is no need to burden people with unnecessary words; people know that a Roc is a huge eagle and that its upgraded form is a Storm Bird - let it remain so.
My idea about the origin of the bird is approximately the same for the Ashan and my fictional world - these are elemental spirits associated with mountains, like Ents, Kirins, Kappas, and others