This has been brought up before
Cataphract Horse
hit points: 120
body armor: 47
difficulty: 5
speed: 38
maneuver: 40
charge: 38
Price : 44.711
War Horse
hit points: 120
body armor: 40
difficulty: 5
speed: 41
maneuver: 41
charge: 36
Price : 33.248
Large Warhorse
hit points: 130
body armor: 43
difficulty: 5
speed: 40
maneuver: 41
charge: 36
Price: 35.196
So, for roughly 10k higher price, cataphract is inferior to large warhorse in speed, manouver, hit points and only has 2 more charge (nothing drastic) and 4 more body armor. Makes picking a cataphract over most of the other heavy horses because of it's stats (and not because of the style) a rather irrational choice.
Now i won't lie , i'm lobbying for a horse i myself am using. But it's a justified request, the stats are way off.
I suggest either improving cata's armor up to 50-52 (next horse,charger, has 58. compare this jump of stats to large warhorse vs cata) OR improving (+1) it's manouverability and speed OR a minor buff to stats + a slightly reduced price.
Either way , some changes should be made simply because as it is now, the balance between this 3 horses is non-existent.