Well in this kind of situation you probably wouldn’t go cataphract as they freaking expensive bc you camels are dirt cheap. With bloodlines they’d have probably the best camels in the game, even cheaper than berbers.
Only 6.25% cheaper in exchange for lacking 2 attack. Byzantines Camel would be still weaker than Berbers. I would prefer 25% cheaper Halberdiers thousands of times over 25% Camels. In Imperial Age, Halberdier is 10 times better than Heavy Camel.
Yes, by in a pinch, Camel Riders can be used as pseudo-Knights, and Heavy Camels as pseudo-Cavaliers, plus they are anti-cavalry themselves and move faster than Pikemen/Halberdiers, so they are quite the good bonus for Byzantines.