Horses are like any other tool in haven, except maybe one of the most used by new players in villages. They are used to travel and carry luggage across the hearthlands. But having a fresh spawned character perfectly control a beast of nature that has an energy unit named after them? Not very believable, also makes the game too easy and spoils new comers. How will new hearthlings know how it feels to drudge across the valley carrying a boat to the docks?
Maybe make a system where when a character tries to use a horse in any way the horse "bucks wildly and refuses to cooperate." To be able to use a horse well maybe the sqrt of will*lore. Depending on the values of the horses stats is how hard it is to control? The best reference I can use is sadly pokemon. If you had traded a lvl 100 pokemon it wouldnt obey 90% time if you were on the 3rd gym and wouldnt fully obey you until you gained the last gym badge to prove your worth.