Here are some ideas on how the game could be more mount-balanced.

Horses

Used to go fast from A to B. Cannot cary much but can be connected to wagons to carry more. Can also be used in combat (doom) or fly (Pegasus) or traverse the desert (Dine) or small bodies of water (forgot the name). Horses are tolerant to cold climate and weak against hot like the desert debuffs.

Donkeys

Slower than horses but can carry a lot more than them. An in-between Horse and Elephant. You can think of it as a good compromise. Can connect to wagons and the stronger the breed, the better the caravan. Shai has exclusive donkey skills like they do today but all donkeys should have this. Donkeys in real life are actually amazing in battle, they are used on farms to fight off predators. Perhaps they could be used on the mansion to keep away pests from the garden? T9 Donkey could glide as long as it doesn't carry anything. Donkeys are also tolerant to cold climate, weak to hot climates like the desert.

Camels

Used to traverse the desert quickly. Cannot carry much but can have a canopy to prevent heat stroke and hypothermia (this doesn't exist yet). Camels could have a heat tolerance unlike other mounts (except elephant) so they wouldn't die in the desert. This mechanic doesn't exist but it could and yes, even dine wouldn't be immune to it. Camel caravans could also exist, so think of them like the donkey of the desert. Weak to cold climate.

Elephants

Slowest of all, but can carry the most. Elephant caravans could be a thing but it'll be slow. Elephant caravans shoudl only be used in desert areas, anywhere else it would be impractical. It would differ from camel because it's much slower. So do you transport more at a slower speed or less at a faster speed? Also tolerant to desert debuffs and can have a canopy.

Bird things from Grana

I forgot what they are called, they look like a chocobo. They're not mounts yet but they could be faster than a donkey, but meant to be used in combat. T9 could fly short distances (unlike gliding like pegasus). Can tolerate some desert better than horse / donkeys but is very weak in cold regions.

I believe cold regions are coming, I feel like I saw an expansion video about it before. Well, those are some ideas anyway.