The following pictures are of the 180 Sassanid Persian armored horse archers and the 72 Byzantine cavalry on partially armored horses. I still have 180 armored lancers to paint for the Sassanid Persians, 144 armored horse archers for the Byzantines, and 144 lancers on unarmored horses for the Byzantines.
To distinguish the Byzantines from the Sassanid the Byzantine cavalry will have iron armor for the partially armored horses while the Sassanids will have bronze armor for their horses. I also gave the Byzantine cavalry red standards and shields while the Persian standards and shields will be in multiple colors. I did try reducing and printing shields from the Notitia Dignitaum, but the images would not print clearly.
The Sassanid Persians