In one of my Pahlava campaigns I had a fullstack of 3 FM's 5-6 armoured HAs (Zradha Shivatir and Daha Uezdattae), 2-3 Azad Asavarans supported by a mötley assortement of different foot archers clash with a Saka fullstack of the same nature. After charging the enemy cataphracts I butchered their foot archers and chased down their HA's with my armoured ones. It took some time but I killed them off eventually.