>>716184984
I don't really play this game that way, so I don't actually know. That said, if you want to take a look at the current meta Kamigame is probably a pretty reputable source for tier lists. Basically every horse is more or less viable in this game due to the legacy stat grinding mechanic.
https://kamigame.jp/umamusume/page/146166686402230480.html
https://kamigame.jp/umamusume/index.html#%E3%82%AD%E3%83%A3%E3%83%A9%E3%82%AF%E3%82%BF%E3%83%BC