I should be clear I am making this term up (at least as far as I know) to make a contrast between what Total War has, which are single units made up of soldiers with identical equipment loadouts that have a dual function (hybrid infantry) and what it doesn’t have: units composed of two or more different kinds of infantry working in concert as part of a single unit, which I am going to call composite infantry.

This is actually a very old concept. The Neo-Assyrian Empire (911-609 BC) is one of the earliest states where we have pretty good evidence for how their infantry functioned – there was of course infantry earlier than this, but Bronze Age royal records from Egypt, Mesopotamia or Anatolia tend to focus on the role of elites who, by the late Bronze Age, are increasingly on chariots. But for the early Iron Age Neo-Assyrian empire, the fearsome effectiveness of its regular (probably professional) infantry, especially in sieges, was a key component of its foreign-policy-by-intimidation strategy, so we see a lot more of them.

That infantry was split between archers and spear-and-shield troops, called alternately spearmen (nas asmare) or shield-bearers (sab ariti). In Assyrian artwork, they are almost always shown in matched pairs, each spearman paired off with a single archer, physically shielding the archer from attack while the archer shoots. The spearmen are shown with one-handed thrusting spears (of a fairly typical design: iron blade, around 7 feet long) and a shield, either a smaller round shield or a larger “tower” shield. Assyrian records, meanwhile, reinforce the sense that these troops were paired off, since the number of archers and spearmen typically match perfectly (although the spearmen might have subtypes, particularly the “Qurreans” who may have been a specialist type of spearman recruited from a particular ethnic group; where the Qurreans show up, if you add Qurrean spearmen to Assyrian spearmen, you get the number of archers). From the artwork, these troops seem to have generally worked together, probably lined up in lines (in some cases perhaps several pairs deep).

The tactical value of this kind of composite formation is obvious: the archers can develop fire, while the spearmen provide moving cover (in the form of their shields) and protection against sudden enemy attack by chariot or cavalry with their spears. The formation could also engage in shock combat when necessary; the archers were at least sometimes armored and carried swords for use in close combat and of course could benefit (at least initially) from the shields of the front rank of spearmen.

The result was self-shielding shock-capable foot archer formations. Total War: Warhammer also flirts with this idea with foot archers who have their own shields, but often simply adopts the nonsense solution of having those archers carry their shields on their backs and still gain the benefit of their protection when firing, which is not how shields work (somewhat better are the handful of units that use their shields as a firing rest for crossbows, akin to a medieval pavisse).

We see a more complex version of this kind of composite infantry organization in the armies of the Warring States (476-221 BC) and Han Dynasty (202 BC – 220 AD) periods in China. Chinese infantry in this period used a mix of weapons, chiefly swords (used with shields), crossbows and a polearm, the ji which had both a long spearpoint but also a hook and a striking blade. In Total War: Three Kingdoms, which represents the late Han military, these troop-types are represented in distinct units: you have a regiment of ji-polearm armed troops, or a regiment of sword-and-shield troops, or a regiment of crossbowmen, which maneuver separately. So you can have a block of polearms or a block of crossbowmen, but you cannot have a mixed formation of both.

Except that there is a significant amount of evidence suggesting that this is exactly how the armies of the Han Dynasty used these troops! What seems to have been common is that infantry were organized into five-man squads with different weapon-types, which would shift their position based on the enemy’s proximity. So against a cavalry or chariot charge, the ji might take the front rank with heavier crossbows in support, while the sword-armed infantry moved to the back (getting them out of the way of the crossbows while still providing mass to the formation). Of course against infantry or arrow attack, the swordsmen might be moved forward, or the crossbowmen or so on (sometimes there were also spearmen or archers in these squads as well). These squads could then be lined up next to each other to make a larger infantry formation, presenting a solid line to the enemy.

(For more on both of these military systems – as well as more specialist bibliography on them – see Lee, Waging War (2016), 89-99, 137-141.)

Bret Devereaux, “Collection: Total War‘s Missing Infantry-Type”, A Collection of Unmitigated Pedantry, 2022-04-01.