In antiquity, the difference between warriors and ordinary thugs and bandits is often hard to see; and, in terms of evolutionary biology, young men are expendable whereas women are not. The Romans, as well as others, took a step toward making the distinction by introducing military discipline.
A “thumbnail” reflection of pre-Roman Europe can be found in the 17th-century missionaries’ Relations des Jésuites, which contains depressingly numerous accounts of wars between North American Indians.
The conflicts had various pretexts, of course, but they were normally struggles for territory or loot. And the violence usually consisted of occasional or continual skirmishes.
Historian Raymond Aron’s “century of total war” would have to await industrialization, three hundred years later. The long war between the Iroquois and the Hurons (Wendake) seems to have been one of an unusual order.