heavy cavalry engaging heavy cavalry

[Flavivs Aetivs]

Well when you look at Byzzie and Sassanid Cataphract warfare, what is commonly recorded is that Horse Archer Cavalry engaged at long range with bows, then retreated into the cataphracts, who would come through the other side of the horsearchers. The horsearchers would then support the cataphracts through missile and lancing attacks. The cataphracts probably would expel any missiles they had, then charge. Flanking attacks are probably ideal.

That's all I know.