Rome is actually a really interesting example for looking at societies through this lens, because in the time period leading up to the Second Punic War, Cannae, and the necessity of pulling another 100k soldiers out of their
asses, they hadn't developed a 'warrior caste' - the legionaries as they're usually thought of didn't exist yet. These were phalanx spearmen raised from their land-owning population that would be going back to that land once the fighting was done, and if you didn't own at least 100 denarii worth of property, you weren't worthy of being in even the lowest rungs of it - not just because they had to supply their own equipment, but also because that meant their first loyalty would be to the society that recognized their right to that property. So they were, like a nomadic society, putting themselves in a position where a bad enough military defeat would gut them. And it pretty much did. In any sane universe, Cannae would have been the end of the story of Rome.