I think you are wrong, more than 2,000 years ago Strabo says about the people who lived in the north of Iran (Mazandaran):
http://penelope.uchicago.edu/Thayer/...rabo/11G*.html "They say that some of the Parrhasii took up their abode with the Anariacae, who, they say, are now called Parsii; and that the Aenianes built a walled city in the Vitian territory, which, they say, is called Aeniana; and that Greek armour, brazen vessels, and burial-places are to be seen there."
Parrhasii seems to be the same
Parhasi (also called Marhasi, Barhasi, Warhasi) which has been mentioned as a major land in Iran from at least the 3rd millennium BC in Sumero-Akkadian sources, names of Parrhasi kings certainly sound Indo-European, for example
Arwilukpi means "king of the free people", compare Hittite
Arawa "free, noble", Indo-Iranian
Arya "noble" and Sanskrit
lok "people",
lokapa "king, world-protector".
Parrhasii can be comapred to Greek Parrhasia and Parrhasius:
https://en.wikipedia.org/wiki/Parrha...son_of_Lycaon) "Parrhasius was in Greek mythology the son of Lycaon or of Zeus. He was an Arcadian hero, and his son Arcas had the region named after him.[1] He is said to have founded the Arcadian city of Parrhasia."
Aeniana can be also compared to Greek Aeniania:
https://en.wikipedia.org/wiki/Ainis "Aeniania, was a region of ancient Greece located near Lamia in modern Central Greece, roughly corresponding to the upper Valley of Spercheios. The region takes its name from the tribe of the Ainianians, who dwelt in the area."
About Parsii, we know Persians still call themselves
Parsi, according to Herodotus, 2,500 years ago Xerxes knew the relation between the name of Persians and Perses/Perseus, the legendary founder of Mycenae. Ancient Akkadian sources also talk about Parsua in the northwest of Iran, the name of this land also related to Greek/Persian words. Of course Xerxes himself knew that the Greek name is the original one.