Zoroastrian and Hindu scriptures: Aryan, Saka, Sakya, Scythian, Tibet

Scythians and Sarmatians (Iranian Peoples) : theravada

You would be interested to read. Some things to consider:

Who are the Aryans?

The Indo-Iranian group whose members composed the Zoroastrian scriptures, the Avesta, and the Hindu scriptures such as the Vedas, called themselves Aryans (Airya/Airyan in the Avesta and Arya/Aryan in the Vedas).
The Zoroastrian and Hindu scriptures are the only known ancient texts that contain references to Aryans...

The languages of the two scriptures, the Zoroastrian Avesta and Hindu Rig Veda, are similar but not identical, indicating that at the time of their composition, the people of the Avesta and the Rig Veda were related and close neighbours...

The two Indo-Iranian Aryan groups eventually ceased to be close neighbours. They separated and migrated to present day India and Iran, becoming Indians and Iranians in the process... 

What I know is - Aryan moon worshipers and Aryan sun worshipers went separate ways. Some of them got to northern India and became Indo-Aryans. They were definitely not Scythians. Aryans are not Scythians.

Sakya is spelling, and Sakiya is the pronunciation as “Sakiyani sākiyānī : (f.) a woman of the Sākya race.” Same to Aryan pronounced as Ariyan. Probably Sakya (Sa-Kya) is also a right pronunciation, not developed later. But the pronunciation does not seem to have any relationship to Saka or Scythian.Aryan Prehistory

the Farvardin Yasht 13.87, recounts that Aryan prehistory started with Gaya Maretan, founder of the Aryan nation. The Shahnameh states that he was the first Aryan King and that during his reign, people lived in the mountains (also see Aryan homeland location: Mountains - Hara Berezaiti) and wore animal skins and leaves. ...

 Probably they dug caves to live inside the mountains. 

During the Age of Hushang, the Aryans developed agriculture and furthered the domestication of animals and - two elements essential for the development of settled, civilized societies ...

The Age of Hushang was therefore the start of the Metal Age in Aryan history. However, unlike other metal ages which started with the processing of copper, Aryan and Saka legends place the use of gold before the use of copper in Central Asia - possibly even a few thousand years earlier. 

Aryan and Saka, two different groups 

Chapter 12: The Worship of the Sun Among the Aryan Peoples of Antiquity - The Worship of Nature

The Indians of the Vedic age personified and to some extent worshipped the sun under various names, of which the chief were Surya and Savitri or Savitar.5 It is under these two different appellations that the sun is chiefly celebrated in the Rig-veda,

India Iran Historical Links

21. The Iranian Surya (sun god) wearing a long coat with a sacred girdle and knee-high boots was worshipped by Indian kings. He had a special name Mundirasvami and the word Mundira is found in ancient Iranian texts from Khotan. The Modhera temple in Gujarat and Munirka village in Delhi remind of the name Mundira. The Sun God at Konarak, Orissa is famous in his Iranian drapery and boots. The royal priests of this royal surya were of Iranian descent like SakadvipiyaBrahmanas, or Mishra (in which th of AvestaMithra became sh).[33]

Median Empire - Crystalinks

The Medes were an ancient Iranian people... arrival to the region is associated with the first wave of Iranian tribes in the late second millennium BCE (the Bronze Age collapse) through the beginning of the first millennium BCE.

Iran Chamber Society: History of Iran: Common Origin of Croats, Serbs and Jats

The name Sarmatian is an Anglicization of the original Sauro Matii, the Latin form of the Prakrit Surya Madra or Surya Mada. The name means "Solar Medes", in English, another testimony to the worship of Surya, or Cyrus, the Asshur of Assyria, the Ahura Mazda of the Zoroastrians, the splendid Sun-god of the Iranic peoples.

...

Scythians – A sub family of Aryans | INQUISITION: 

...the ARYANS and SCYTHIAN.  There has been a substantial finding by many scholars, who classify Scythians as a sub-family of  Aryans. As these Scythian were the Eastern European-Indo-Iranian proto people who migrated into north India in 2 century BC. There is always a likelihood of being identified differently from the original Aryan natives in India who have been living there since 4ooo BC. ( at least of what is known.) ... 

If ancient Aryans (Sakyas) lived in northern India since 4000 BC, then compare this with the Medics or Surya Medics and their arrival to northern Iran by 2000 BC as stated above.  Sakya might not be related to Surya Madas. 

Aryan Saka, Scythia & Scythians

Where Have all the Saka Gone? Saka & Turkic Peoples: 

Today, the traditional Saka lands around the southern banks of the Aral Sea and along the banks of the Syr Darya River (northern Uzbekistan and southern Kazakhstan), are inhabited by a people who speak a Turkic/Altaic language and who are sometimes called the Turkoman... However, the appearance of the Turkic peoples and the establishment of the Turkic language in these areas is a relatively modern phenomenon... The Altai-Turks made up the bulk of the invading forces. After the Mongol invasions led by Genghis Khan (c. 1162-1227 BCE), Altai-Turkic peoples quickly poured in to the conquered lands displacing the aboriginal Saka and Turanian inhabitants

The Sakyas lost war and moved to a new region. The Sakyas found Kapila (also see this book on page 184 - Chapter IX), built their city and named it Kapilavattu in probably between 600-700 BC. 

Aryan Saka, Scythia & Scythians: 

[Reader's need to make allowance that many ancient and modern writers were and are not scientific or circumspect in their writing. Many filled the gaps in their information with their imagination or skewed information to support a political or racial motive. For instance, Greek writers added to their substantive and convoluted mythology that the nations of Persia (and Media) were formed by Greek gods. Expropriators of The Irano-N. Indian Aryan heritage (including symbols) claim eastward migrations of their 'race'. Other machinations had the Caucasus Mountains as a birthplace of the white Caucasian 'race'. At one time, the Soviet Russians actively promoted the concept of eastward 'Scythian' migrations perhaps to bolster their imperial acquisition of the once Saka lands in Central Asia...

Did Kapila the name of the ascetic come from Kapila the name of a plant? 

Kapila (page 138): Kamala consists of the red glands that form on the fruit of this tree, which grows throughout tropical India. The drug is a red, heavy powder, somewhat gritty, insoluble in water, but partly dissolving, with an orange color, in alcohol. This drug is used as an anthelmintic. Formerly employed as a dye for silk and wool, it has been almost entirely replaced by aniline dyes.

 Another link about Kapila plant 

Zoroastrian Heritage: Iranian-Aryan Connections with Western Tibet

 Tucci and Samuel further state that the objects bear a striking resemblance to those found in the western Iran province of Luristan / Loristan indicating a connection if not a trading relationship between the Iranian and Tibetan cultures along the Aryan Trade routes. Luristan straddles the Zagros Mountains. The bronze objects are dated from the first to the second millennium BCE and are thought to have been made by the area's Kassite inhabitants (see Luristan Bronzes by Donald Wilber).