>>724566397
Sharing the sane name means they had the same owner pretty much, like Narita Brian / Taishin / Top Road. The Mejiros and Satanos were turned into aristocratic families in-game though. Because of the way horse breeding works IRL where one stud can be put out to seed dozens of mares, they just largely don't consider them family unless they had the same mom. Otherwise they would have a lot of sisters.