How much did warfare change between Classical Athens and Sixth Century East Rome? And if it did was it an improvement? Was there anything that could be considered a revolution? Some say there have been a number of military revolutions (er - that's revolutions in the ways of war, rather than, say, the replacement of one ruler by another) at various points, other just a few. Had matters improved to such a degree by the sixth century that an east Roman army would annihilate a band of Athenian hoplites had they jumped forward in time some 1000 years?
The most obvious answer is probably yes. After all, the hoplite armies of late classical Greece had been defeated, quite significantly, by those of Philip, Alexander, and Macedonia. In turn, those same Macedonian armies had been defeated, in time, by the Roman armies, and again quite significantly. So, if the sixth century east Roman army was an offshoot of the earlier one that had been so successful, then it would stand to reason that yes, they would be successful, and so things had improved.
But was there anything that could be called revolutionary in the changes that had taken place? There was no gunpowder, or air power. Even the stirrup wasn't quite there yet. What about changes in artillery: do they count? Perhaps, but did victories in sieges ultimately lead to success in war? The Romans had a lot of success, but so did the Persians - and they eventually lost out. Perhaps if there was a revolution it was less in the area of the methods of fighting than in the organizations that emerged instead. The Roman armies were famously professional - eventually - and the greater flexibility of their units allowed them to run circles around their foes. Polybius describes something to this effect in his Histories when he's describing the Macedonian phalanx and the Roman legion (which in his day was filled with cohorts rather than centuries, which came a bit later). Sarantis (2013) has argued that Roman success in late antiquity rested in another aspect of organization - their infrastructure, from the series of well-fortified sites across the frontiers to the well-planned logistical networks and systems. So maybe the revolution, or revolutions, was less in the way of war than in the means of enabling it.
Much of our evidence for combat, of course, comes from literary sources, and their take on things can muddy the waters to no insignificant degree. To my mind one of the most stark examples of this is Procopius' descriptions of combat in his Wars. For Procopius is effectively describing war in the language, manner, and style of Thucydides, even though Thuydides is dealing with hoplites and Procopius late Roman soldiers. Even more surprising - and problematic - than this is his "famous" comparison in the preface between Homeric archers and the horse archers of his day. Scholars have wrangled over what Procopius is saying: legitimate discussion, playful and subtle criticism of contemporary practice, or the presentation of some sort of ideal. Whatever he had in mind, it's worth considering that he did see fit to make this comparison in the first place, and his relative success as a writer suggests it had some currency. Is this just a case of the baffling ineptness of Procopius and some members of his audience? In some real sense did they really think that you could compare the warfare waged 1000 years (and more - even 1500) earlier with that of his own day? Had some actually criticized the present-day soldiers in light of those earlier ones?
But maybe we are missing something - maybe war really hadn't changed all that much. Yes, Roman legions had crushed Macedonian phalanges/phalanxes, but if Alexander had lived a little later, and/or the two met a bit earlier, would the phalanx still have been bested by Roman might? I think that question is harder to answer.
Ultimately, a satisfactory answer would take a lot more time and space than the length of this blog and the amount of time it took me to write this. But, if warfare didn't change all that much, at least during the classical age (and you might say Homer and Procopius fall outside it, to some degree, at least when we're concerned with warfare, and so the notes about them are misleading), that Procopius, for instance, did see fit to describe war in the manner that he did might not have been as foolhardy as it might seem on the surface.