The Immortals

[hoplite14gr]

Persians did have hevy infantry.
Their tactisc were not developed arround it though.
An propably it was a slower evolution than in Greece.

They could maintain formation but they could not easily execute othismos. In Marathon it seems that spear armed Persians ans Sakas were at least 4 ranks deep like their oposing Atheninans and had initial success.

It seems that there was a lack of proficient spearfighting infantry in the Persian Army as the Thrmopylae showed in the 2 day fighting.
Carians, Lykians and Ionian Greeks who fought hoplite style were in the fleet fighting in Artemisium and did not fight the defenders of Thermopylae.

The weapon that Greeks dreaded was the "saggaris" the axe with the spike. It probaly caused the heavier casualties in the woods of Marathon where the hoplites could not fight as a Phalanx. It also aided the defnece of the ships. Kynageiros was probably killed when the spike of a saggaris was driven throuhg his helmet. Helmes with saggris marks exist in Olympia museum

Greek writers say tht Persians did not lack courage but they did not have the propr tactics. Perhaps because if you are the Persian king na have 25000 talents pe year you could hire ready trained hoplites.

It was not a question of having heavy infantry but if it was employed correctly which more often it was not
Plus it is very questionable if you use the shield with the scalops in othismos

Kind regards