Phalange Mixte

[Sean Manning]

Unfortunately no clear description of the levies of Cyrus is available.

....true, but we do have significant evidence for later Achaemenid organisation, and it is a reasonable assumption that Cyrus/Khurush's Persians were similarly organised.
Persian society consisted of nobles,(azata) who, like later feudal structures owed their lands and allegiance to the King, and were in turn served by 'bondsmen/retainers' (bandaka). Military Service was compulsory for all between 17 and 50 ( and only the King could grant exemption, according to Xenophon (Cyropaedia VIII.3.47). At the bottom of the social pyramid were the serfs/slaves who actually worked the land (mariaka)
The army itself was organised into units/regiments of one thousand (Hazarabam ; Gk: 'myriad') divided into ten companies of 100 each Satabam, divided in turn into files of ten men called Dathabam, with a file leader Dathapatis (who was presumably the sparabara/ shield/pavise bearer), 8 archers and a 'file-closer/second-in-command' bringing up the rear (Pascadathapatis lit: after/rear file leader). These details come from Aramaic documents and ration states from garrisons in Egypt, which also reveal, as one might expect that actual strengths of the company/satabam were frequently 60 or so rather than the 'paper' 100, and sometimes fell as low as 30-40. It seems that the filedathabam was kept at 10 men in such cases. Xenophon also refers to units of these sizes, though giving Greek equivalent names.
There were also Divisions of Ten thousand,(Baivarabam) the most famous being the King's personal Division, the 'Immortals' (Amrtaka) whom Herodotus (VII.40-41) tells us were so-called because they were always kept up to strength.

I should point out that we don't know the exact makeup of these mixed formations of pavise-men (OP sparabara) and archers. Herodotus describes his generic Persian soldier with spear, woven shield (gerra), bow, dagger, and sometimes scale armour. He tells us that the army had a decimal organization, which other sources confirm, suggesting a nominal depth of ten men. The Jewish-Aramaic Garrison at Elephantine was organized into squads of 10 or 11 but we don't know if they were sparabara. It seems likely that the middle ranks didn't carry the shield, because Herodotus tells us that once the shield-wall was down the Persians had no shields to defend themselves. Did the middle ranks carry spears into battle, and if so, what did they do with them when shooting? Did the file-closers have shields too? How many ranks of archers could shoot at once?