Persian Riders in the Aethiopica of Heliodorus. A reliable source?

The description of the Persian Riders in Aethiopica of Heliodorus is often regarded a reliable source to reconstruct the tactics and armament of Iranian heavy cavalry of the Sasanian period, sometimes even spread to its Roman equivalents. The conventional nature of entire text is somehow disregarded in this particular point which is not less conventional than all other depictions of the novel. The description uses fixed phrases designed to flatter the erudite reader, not to describe actual combat troops of Achaemenid era disguised in fourth century attire. The Heliodorus’ description must be treated with utmost carefulness and can be a tertiary source for reconstruction of the Sasanian heavy horse, at best.