Rome was post-scarcity. The Roman Empire was not. There's a distinction.
I've read Gibbons, Tacitus, De Re Militari (Vegetius), Mary Beard's several works, Pax Romana, several works citing the dramatic fall in literacy from 30-50% to less than 5% following the Antonine Plague, The Rise and Fall of the Roman Empire, more than a few documentaries, several books regarding the Eastern Roman Empire including Lost to the West, and most importantly hundreds of posts with the people who have written every Roman Book in the last 15-20 years.
If Roman History interests you I suggest you post on Romanhistorytalk.com.
Fun fact. Carthage had the equivalent to the United States Navy in modern terms. The Romans, nothing comparable. A Carthaginian ship became trapped on Sicily and was captured, and the Romans deconstructed it realizing all the parts were marked like furniture from Ikea. Within a year, the Romans had the largest navy in the world.
They sent they navy towards North Africa, it beat the ship out of Carthage and on their return was hit by the Mediterranean equivalent of a Hurricane. 95% of the ships and troops went straight to the bottom, including 100,000 soldiers.
Btw, ancient suggestions at the numbers involved in the battles are not overrated. Rome had the logistics to field that many men, including the population in the Empire. The reason Medieval battles were fought between a few thousand vs a few thousand was the decentralization of the Feudal system, the rise of the Knight, and the inability to provide logistics for such large armies, including the fact that the population of Europe SHRUNK from Antiquity into the Medieval period due to Smallpox, the inability to feed people, and other factors.
Rome had a massive, massive population. It relied on food from other countries to support it. When that no longer existed, the population of Europe collapsed for a thousand years (including the Black Death).
When you read about battles between 80,000 soldiers vs 80,000, we know they're true because we KNOW the size of Legions. Legions had 10,000 men each, and we KNOW how many Legions participated in each battle. When 8 Legions participated in battle, that was 80,000 men.
You could take the Roman Empire and drop it 1,000 years into the future, and it would have easily defeated every Medieval army that fought it. Their technology wasn't far behind, in fact it was ahead in several aspects like mobile artillery, and they had far better logistics. You'd have disciplined legions numbered in the hundreds of thousands vs say Edward's army of 10,000 at Agincourt. Instead of Edward facing undisciplined Knights eager to charge, he'd have had to deal with a massive amount of heavy infantry careful to trod across muddy ground. His longbowmen (a drastically overrated weapon) would've been of little use as there would be no horses to shoot from underneath their riders. The Roman ballistae would have fired upon the longbowmen far before the longbowmen were in range, forcing Edward to abandon his position or advance.
At least one modern historian agrees with me:
Dan Carlin claims that "You could take the roman army at it's height in history and send it 1000 years forward, drop it back in europe [...] and have it mop the floor with the greatest armies of the early middle ages relatively easily". How true can we assume this is ? • /r/AskHistorians
Gibbons claimed that prior modern times, there was NO better time to live than during Pax Romana. 400 AD-1600 AD were comparably horrible times in terms of quality of life.