And where are you getting the gold to fund this? Because it isn't from the HA.
Both my HA and HX uses exactly same armor. With same horse, max upkeep is:
HA: 3,717 gold
HX: 3,241 gold
So that's about 12% upkeep difference in favor of HX. Not big one, but yeah, HX is slightly cheaper to play.
My Shielder and 2h chars has max upkeep about 2.5k. With those classes i'm not losing money, but even make some.
Why is upkeep so high for HA/HX? I guess it's just part of devs solution to keep people away from playing those classes.
I really don't see HA as weak class comparing to HX. It's just different class. As HA I focus enemy horses and infantry, as HX I focus enemy ranged and horses. HX is easier class to play, but that also means it's relatively easy to max out your potential as HX (which isn't that huge!). Since HA is harder to play than HX, it's also much harder to master it, so it has greater potential (especially i'm doing fine even now, as HA newbie).
Imo HA/HX in term of efficiency are no match at all to 2h or any other proper class. I can decide about battle win if I have good round as Shielder or 2h. As HA/HX it's almost impossible to affect battle itself - before I kill 1 target, battle is often in ending stage already. I can kill some more enemies then, but it won't affect battle result anymore, battle is basically over. But I like it anyway, playing HA/HX is always something different.