The book "Shahname", translated to "The Book of Kings" which is referenced in the article is not the first occurrence of these legends and mythologies. They are

The book "Shahname", translated to "The Book of Kings" which is referenced in the article is not the first occurrence of these legends and mythologies. They are a collection made of much older folklore stories. While you can find Iranian girls nowadays named "Helia" or "Atena" which came from greek (a testament to Greek influence) but these legends date back to before the Greek invasion. But yes, as you mentioned, they run deep in Indo-European cultures.