Probably he has some Slavic origins. If you still maintain contact with him, it would be interesting to know from which place of Greece he's coming from. Still, I doubt he can surpass
al-Douri, who looks more like a British investor in London, instead of an unrepentant Iraqi Baathist and the current head of the Naqshbandi Order. As for Agesilaus and Julian, I'm not sure how reliable these accounts really are. Xenophon's biographical works are closer to rhetorical encomiums than historiography. The episode doesn't make much sense, to be honest, and by the way, it doesn't necessarily refer to horsemen. The
passage says that the Persian captives were soft, because they traveled upon wheeled vehicles (
ὀχημάτων), which presumably refers to either chariots or carriages. This sounds more like a stereotypical caricature of Oriental luxury than a genuine description of a not particularly efficient stratagem.
In what concerns Julian, the affair is probably invented out of thin air. Ammianus Marcellinus, who is, I believe, the author of the statement, consciously tries to imitate Xenophon and compare the Roman Emperor Julian with the Spartan King Agesilaus. Xenophon has been traditionally been the idol of military historians and biographers of Antiquity, while the insistence over Julian's frugality and ethos are clear allusions to Agesilaus, whom his Athenian employee had established as the ultimate paragon of moral virtue. Consequently, it's safe to assume that either Ammianus or Julian (both of them exceptionally acquainted with classical literature) attempted to copy Xenophon and Agesilaus respectively (the expedition in Sassanid Mesopotamia providing obvious parallels with Sparta's campaign in Achaemenid Anatolia), but the former hypothesis definitely sounds more plausible to me.