This discussion of the Indo-European homeland of the Caucus and Scythian peoples is fascinating. Jorjani has a grasp of etymology that helps him dial in and focus on the true origin of peoples on a cultural level.
I have done significant research on this period and region. I suggest reading:
-Amazon by Steven Pressfield
-Soldier of Arete and Soldier of the Mist by Gene Wolfe, which can be had in the omnibus edition Latro in the Mist
-The Cyropedia by Xenophon, of special significance as Xenophon was an adopted Spartan who fought against the Persians
-Cyrus by Harold Lamb
-By the Wine Dark Sea by James LaFond
-The Anabasis by Xenophon
And anything you can find on Alexander, who devoted himself to amalgamating all Indo-Europeans under one rule. Alexander adopted the mother of Darius and he and his men married Persian women.
Jorjani’s illumination of Indo-European metaphysics, particularly the Promethean vision is an idol-smashing revelation. I much enjoy this interpretation and hope to see Jorjani expand his work in print.
Because of the recent submergence of Greece under Turkish rule and the corruption of Balkan Culture due to centuries of Ottomon hegemony, from the mid-1400s to mid-1800s, readers in Western culture have recently abandoned reading of the Hellenic Canon of literature for slimmer Nordic offerings. This is a shame, For a view of ancient Greece from the standpoint of the mature Germanic perspective before the disaster of 1914, read: the Greeks and Greek Civilization by Jacob Burckhardt, n art historian whose reading of ancient classics was so heretical that he would not permit its publishing until after his death.
For Jorjani's points on the Sarmatians and the Arthurian legends see the movie staring Clive Owen as Arthur, which was tolerably made and not overly PC in nature for a modern movie.
Actually, years after the battles of Marathon and Thermopolye, the Spartans did ally with Persia. Aristotle’s views on later Persian despotism should not be jettisoned, however they should be put in perspective. For a brief on how Persian metaphysics were overcome by Islam see Stoddard: The New World of Islam.
In terms of kingship and martial history, the Persian empire founded by Cyrus was tribally pluralistic, with many nations under one big tent. This was the basis for a fairly flexible, but not always wieldy, military makeup in which the variety of tribal nations, bringing their various traditional weapon forms, which infuses the army with a certain amount of built-in flexibility in that it was a combined arms formation. In the Middle Ages this structure was typified by the king drawing heavy horse from the nobility and various forms of lightly armed infantry and light horse from regional borderlands, with specialized artisan types [such as siege engine companies, handgunners and crossbowmen] being drawn from townships and small cities.