Baktroi Hippeis can be used as a good shock cavalry, but are not meant to stand up to Kataphraktoi.
The Baktrioi Hippeis under Hellenic rule represents a cultural fusion that makes the legendary horsemen of Baktria even more formidable. Armed with an axe and a two-handed lance, these men are armored in the finest Hellenic bronze, and fight with a level of ferocity not usually found in regulars of their type and station. While not as heavily armored as Kataphraktoi, they are still able to hold their own against most other cavalry, in that they are far more heavily armored than is the norm. They should be used as shock cavalry, but must be wary of heavy infantry or other heavy cavalry.
Historically, the Baktrioi Hippeis were among the most famous in the ancient world. Arrianos relates to us the curious story of their Nisean horses being fed only flowers, such was the quality of the breed and the delicate nature of their diet. This made a strong, powerful horse that was to form the crucible of war horses for the great eastern kingdom. Representing a fusion of Hellenic and Iranian, these men made up the local nobility in which 'mixed' families often ended up. They were not wholly Hellenic and not wholly Baktrioi, but they were loyal enough to the State to provide heavy horsemen that helped stem the tide of being surrounded by foemen.