Coherent and single-minded infantry formations are an idea dating back at least to the Greeks from 2,000 years earlier. Training, not technology, was the dominant force.

I don't have the right background to comment on the rest of the quote, but I can tackle this bit. While the author is on the right track with the assertion that disciplined infantry formations tend to hold their own against heavy cavalry, their understanding of the history of this military formation seems limited. Everything they're saying here about the Greeks is plainly wrong.

To be fair, they qualify their claim with the words "at least", allowing for the notion of infantry formations to predate the Greeks. It does, indeed, predate the Greeks by another couple thousand years. One of the earliest unambiguous pieces of evidence for a regular, close-order spear formation is on a Sumerian stele dating to the 2400s BC. The Assyrians of the first millennium BC are also known to have relied on heavy spearmen to form the backbone of their armies, suggesting a steady tradition of spear infantry formations in Mesopotamia.

The Greeks were late to this party. While we have some evidence for heavily equipped infantry in the Mycenaean period, helmets and body armour disappear from the record for 400 years after the fall of the Mycenaean palaces, which suggests that there was little focus on close combat. The date suggested in the article you cite (2,000 years before AD 1200 = 800 BC) is much too early; it would take centuries more for the small bands of elite warriors that carried heavy armour to adopt regular formations in battle.

But even when they finally did (probably around the time of the Persian Wars or shortly after), it would be very wrong to say that they were defined by "training, not technology". Certainly during the Persian Wars it was the Persian army that was the more trained, experienced, and disciplined. The Greeks (as our main source repeatedly says) stood out mainly because they had bigger shields and carried longer spears.

Now, this is clearly an oversimplification; in reality it was their high morale and stubbornness, along with numbers and a hefty dose of luck, that won the day. But it certainly wasn't their training or discipline. Greek heavy spearmen had no training - or at least none of the unit drill that makes infantry formations cohesive and effective. We have no evidence of any Greeks (other than the Spartans and Spartan-led troops from the Peloponnesian War onward) ever training together, practising manoeuvres, or carrying out battlefield movements that presuppose unit drill. Greek armies were militia armies called up at need; their organisation and tactics were of the most basic kind, so that even random guys fresh from the farm could be relied on to do their part.

This is not to say that their infantry formations weren't "coherent and single-minded" - but that was because of their shared dedication to the cause, and to their friends and fellow citizens in the line, not because of superior training. It was not until the Macedonians introduced the pike phalanx to Greek warfare in the mid-4th century BC that regular unit drill became essential to the functioning of infantry formations. But these professional pikemen were not created to fight heavy cavalry; they were accompanied into battle by shock cavalry, whose job it was to drive off enemy horsemen. The purpose of the first pike infantry was to confront and defeat the enemy's heavy spearmen.

What's the point of all this? Well, first to show that it's bad history to claim that the Greeks stood at the cradle of some general European or "Western" tradition of heavy infantry fighting. But also second, to show that military history is often much more complex, counterintuitive and contradictive than these simple summaries make it seem. The history of tactics is not a simple story of rock-paper-scissors, but a long history of different people responding to unique situations in ways that were limited by the social, economic, and political conditions in which they lived.