Apologies in advance if this doesn't make sense. If it doesn't, I'll fix it tomorrow.
For the Hylian Troop Tree, and potentially others, like Ordona if they are ever added. Would it make sense to structure the cavalry like at the bottom of this troop tree?
Have every level of infantry have a cavalry equivilant. I like the idea of complicated troop trees, so this might not be for everyone, but it seems somewhat intuitive as a means to acquire cavalry.
So Hylian Recruit goes to Hylian Mounted Recruit or Hylian Swordsman.
Hylian Swordsman goes to Hylian Mounted Swordsman or Hylian Veteran.
And so on.