Here is what we know about the Steppe Iranic languages mostly. For 3/4 we have no clue about the potential borrowings in the grammatical structure. Khotanese Saka is the best attested. Basically, because it was close to the Indosphere and got absorbed.
There is a high possibility that the Barmakids weren't actually SC Asian Persians but Kashmiri/Gandhari Brahmin Buddhist converts that later converted to Islam and we're wazirs of Abbasid dynasty in the Islamic Golden age.
This account has ~50-100 real followers but someone seems to have blocked me or reported this account so it's not able to send notifications to others. Don't understand how to cure that now 🤷🏻
The tribe Alans were the only ones on the steppe who perhaps used the term RELATED to *arya as a self-designation. No other group did. But there is significant scholarly support that the term actually comes from *aryana and not RITUAL *arya directly *aryana means "of aryas"
Autosomally, too, I believe the earliest samples are much different from proper Andronovo-derived Steppe groups. Interestingly, these lands have long been recorded as the area called Ariana (~250 BCE) by Eratosthenes. Much like *Aryana, which the Alans apparently borrow from!
The Younger Avestan text Frawardīn Yašt 13.16 mentions a figure named Gaōtəma, whose name is linguistically cognate with Vedic Gotama. In his paper "Contending for the cosmos: a Zoroastrian poet’s mysterious rival"
The episode may preserve a memory of religious competition between remanent Vedic and Avestan traditions. Which also perhaps alude to the fact that perhaps concepts like Gotras (this obviously wasn't the original Gautana!) were present in Iranic lands.