In general, the mount's rank should be related to the price of the mount as well as the faction characteristics.    But for High elf, mages can ride horses at rank 7 but the Archmage must reach rank 11 to ride a horse. And the great eagle(price: 800) for Archmage is a mount of rank 16.In the other hand, the Astromancer can ride the Grear Moon Bird(price: 1700) just at rank 13.    It's strange, right?