Iran don't really comfortably fit with militarist imo.
Almost no wars in this era. And most of their wars in contemporary era are defensive (from Irak for exemple).

Polish are a defensive culture in early modern, but their military class was famous to be one of the best of the era. 
Iran instead is not considered to be really strong in contemporary era, and is not famous for having any singular and strong  military stuffs as other potential  militarists of the era or comparing another period of iran history where they are really elites  of warriors 

In fact they are just diplomatically and politically alone currently, but it's not because other countries "dont like you" than you are a good militarist. 

IIRC At their "power peak", in contemporary era, their main strengh was their influence, softpower on other islamic countries and their funding and training for external military or religious groups. So Aesthetr fit maybe better gameplay wise ? . 
But their influence today weaken a lot, with all the international punishment and ban. 
And now it's Turkey which have a  big influence, and softpower in the region. And acted more as militarist in contemporary era than Iran which is more in a sort of cold war behaviour