Thank you, as you may know the elite of the Parthian Army are the Savaran or cataphract, but did you know that early Parthian Savaran don't really armed them in iron but leather lamellar and bronze lamellar and scales due to the scarcity of iron. At first cataphract's was to hunt down light horse archer, the cataphract's war gear consists a Kontos lance, and a compound bow with a quiver of arrow, later their role changed as they encounter new enemies notably the Romans. By the 3rd Century CE, cataphracts in iron armor began to appear in the battlefield which indicate the evolution of the cataphract and the purpose of the cataphract due to the prolonged war against the Romans. These iron cavalrymen will become clibanarii by the Romans and eventually the Romans create their own clibanarii to counter the Parthian and later Sassanid threat.
These are units of Pahlava from Euopa Barbarorum or EB:
Shivatir-i Pahlavanig (Parthian Horse-Archers)
Dehbed Asavara (Parthian Noble Medium Cavalry)
Azad Asavaran (Parthian Noble Cataphracts)
Grivpanvar (Parthian Late Armored Elite Cataphracts)
Marda Shivatir (Mardian Archers)
Parthohellenikoi Thureophoroi (Parthian Hellenic Infantry)
Gund-i Nizagan (Parthian Spearmen)
Parthian army relies on horse archer and armored cataphracts but later as they annexed Persia and Mesopotamia local levies and foreign mercenaries was raised to fight under the Parthian banner.
These are the Sassanid Armies from IB:SAI:
Savârân-î Grivpânvâr
Pushtîghbân Grivpânvâr (Elite of the Elite)
Zhâyedân Grivpânvâr (Immortals in Pahlavi)
Jân-Âvspar (Religious Nobles)
Tabargân-î Daylamîg (Elite Infantry)
JangAvaran-i Sassani (Heavy Infantry)
Paighân-î Sassâni: (medium infantry armed with spears and large shields)
Payâhdag-î Nîzagân (Levy Spearmen armed with shield and spear)
Kamândâr-î Payâhdag (Foot Archers)
Kamândâr-î Shahi (Elite Foot Archers)
Sêlâbgandân-î Kôrdîg
Sassanid Empire have standing army, making them a difficult opponent to the Romans.
These are the foreign warriors who served the Sassanian army:
Savârân-î Kûshânshahr
Dawsar
Aspet-i Armeni Lancers
Pîlbân
Arteshtâr-î Daylamîg (heavy infantry)