Would it be possible to relook the internal balance of horses as well? Right now all the horses are quite weak which makes Arabian and Courser arguably the best choices for now. The medium horses like the warhorses can't take any more arrows anyway as the armor level is so low. Here's a comparison between a couple of horses:
Arabian Warhorse vs Barded Warhorse
+14 armor, -6 maneuver
Barded vs Large Warhorse
+5 armor, -3 maneuver, -1 speed
Large vs Cataphract
+9 armor, -1 maneuver
There are slight differences in HP between these as well, but nothing major so a direct comparison like that should be fine. For me it looks like the warhorses are terrible compared to the heavier ones like the Cataphract or Charger, while the light horses with high speed or high maneuver are a bit too strong compared to the medium horses. Mamluk again is terrible compared to the Cataphract. Otherwise the idea that there's two different type of horses, fast bump cav and agile melee cav is nice. The high bump damage can really help at times.
PS: Eastern Horse still has the broken model, ever since it was added and reported multiple times.