Why were horses in ancient Europe better than those in China?

First of all, foreign horses and China horses have different breeds. Horses in China are all Mongolian horses, with short stature but strong endurance. Horses in Europe are heavy horses. One of the differences between Chinese and foreign horses is the sprint ability. Take British thoroughbred horses as an example. It takes less than two minutes to sprint for one kilometer, but China horses can't. One more thing, China horses have the advantage of roughage tolerance. China horses can dig grass roots for food in the snow when there is no feed (as happened in the western expedition of Mongolia), and gain weight quickly when there is enough feed. Foreign horses, especially war horses, are fed more carefully, and oats are more common as concentrated feed. In fact, the best horses in the world are thoroughbred horses from Central Asia and Arabia, the best thoroughbred horses in the world. The British thoroughbred mentioned above is also bred through continuous hybridization. During the reign of Emperor Wu of the Han Dynasty, in order to obtain the excellent bloodline of Blood BMW, he went to the Western Ocean to Rouguo many times, and it still exists today. I can't remember the specific name. I'm sorry, but it's a pity that the horse system in China is too closed to improve horses better. The best way is to improve the three hippos with backache. Foreign horses are heavy horses, compared with Mongolian horses, they are light horses, so the eastern and western cavalry also have relative weight