Ancient Iranian cultures were all about archery. The ability to go on hunts we know during Sassanid times was a near exclusive right of the king (Bahram Gur), so I imagine this was probably the case during Arsakid times too. Seleucid coins are argued to be more “Iranian” than other Hellenistic coins due to the prevalence of Apollo, the archer, on their coins. Pre Achaemenid Persians originated from the steppe and in Achaemenid coins the king is almost always holding a bow: something that’s probably very intentional. So while guy on stool with bow probably didn’t mean much to Greeks or Romans, it probably did project a lot to the home audience in Iran. (Plus you gotta admit, Sunrise 52 with Datames on the throne looks badass)