There were certain unit types throughout history which utilized the potential of the team, Grossman usually calls these "crew-served weapons".
The first one was the chariot which was a genious idea for several reasons (most likely unknown by contemporaries):
Several factors were at play here — the bow as a distance weapon, the social distance created by the archers' having come from the nobility, and the psychological distance created by using the chariot in pursuit and shooting men in the back — but the key issue is that the chariot crew traditionally consisted of two men: a driver and an archer. And this was all that was needed to provide the same accountability and anonymity in close-proximity groups that in World War II permitted nearly 100 percent of crew- served weapons (such as machine guns) to fire while only 15 to 20 percent of the riflemen fired.
The second one stretches the boundaries of the "crew-served" expression, however it really enables anonimity with it's relatively uniformed equipment and order.
The chariot was defeated by the phalanx, which succeeded by turning the whole formation into a massive crew-served weapon. Although he did not have the designated leaders of the later Roman formations, each man in the phalanx was under a powerful mutual surveillance system, and in the charge it would be hard to fail to strike home without having others notice that your spear had been raised or dropped at the critical moment. And, of course, in addition to this accountability system the closely packed phalanx provided a high degree of mob anonymity.
Times fly by:
And when gunpowder was introduced, it was the crew-served cannon, later augmented by the machine gun, that did most of the killing.
Then:
During World War I the machine gun was introduced and termed the "distilled essence of the infantry," but it really was the continuation of the cannon, as artillery became an indirect-fire weapon (shooting over the soldiers' heads from miles back), and the machine gun replaced the cannon in the direct-fire, mid-range role.