Hullo
Could I explain some mythology and ask for your comments or advice?
Persia was involved with Neo-Babylon as the title Kambujiya is seen in Babylonian kambuzi robe worn by Kurus II son in 536 BCE during his kingship ceremony of Babylonian rituals. I'm looking for the Sumerian-Akkadian legend of the eagle god with a thunderbolt in other nations but it appears that Persia was not the transferer of this Babylonian heritage. Ninurta the eagle man had a 3 pointed vajra to attack Anzu. Marduk was no eagle and had a 3 pointed arrow against Tiamat.
Ahura Mazda was an eagle man but had no thunderbolts in his hand. In the Vedas, Indra strikes with vajra, but in the Avesta vazra is Mithra's weapon who is not an eagle man.
Avesta Yasht stanza 10 : vazra - steel resplendent as gold, covered in sharply pointed studs, same as Indra vajra.
The triple-pointed thunderbolt of Ninurta appeared on Greek Olympia coins of 4th cent BCE century.
Jupiter was not an eagle ( although he owned one ) and didn't have a 3 pointed vajra.
Sanskrit Mahabharata was written around that time and Indra a deity of Zoroaster Vendidad used a vajra . No Hindu or Buddhist artwork is known from that era so the shape of the thunderbolt vajra in dharma religion from that time is unknown.
The worship of Nergal does not appear to have spread as widely as that of Ninurta but in the late Babylonian and early Persian period were invoked together as if they were identical. Hymns and votive and other inscriptions of Babylonian and Assyrian rulers frequently invoke him. Nergal represented summer solstice and was god of sunset.
In Sanskrit, Aquila constellation is called Sravana "July-August". Aquila "eagle" stars are the location of Zeus' , Jupiter's and Garuda eagle.
Similarly, both Babylonians and Sumerians called A mushen , mushen "bird" the Altair “the eagle star ”
In Sumerian and Akkadian mythology, Anzû is a divine storm-bird and the personification of the southern wind and the thunder clouds. This demon—half man and half bird—stole the "Tablet of Destinies" from Enlil and hid them on a mountaintop. . According to one text, Marduk killed the bird; in another, it died through the arrows of the god Ninurta.
Ganymede is abducted by Zeus, in the form of an eagle, to serve as cup-bearer in Olympus. So only Ninurta and Zeus are eagle-man with 3 pointed vajra .
So then do you agree that Persians and not Greeks were the means to take the original legend to India ? They both influenced India but the legend appears again in the eastern parts of India's realm many centuries later.