I love this game so much!! Its amazing. But, when you import a horse to show jumping, its jumping ability is determined by how tall it is, its speed by how long it is, and its turning radius by how wide it is. In the real world, really small horses can be fantastic jumpers, and the thick and muscular American quarter horse is the most agile breed. I think that maybe as an update, horses should have different amounts of ability in different areas independent of their physical attributes. They should be able to be inherited but not customized by the horses owner.
The Romulan Star Empire⚡️ about Jumpy Horse Breeding, v1.7