We should make usual horses more expensive. Or just divide all horses into groups
- mundane horses (rouncey, palfrey, sumpter)
- speed horses (courser)
- maneuver horses (arabian horse, arabian warhorses)
- medium tier warhorses (from destier to large warhorse)
- high tier warhorses (up to mamluk)
- superbeast elephant
So we will need more horses for each group. Though i doubt it will be implemented.