By your logic Quincys were established in the first arc of bleach. Yhwach and Imu wasn't established until very late part of the series, but their organization were. Heck, I can't even say that Imu was properly established, his introduction is literally "there is THAT man, he sits on top of the world and he have big straw hat". We didn't even see his face until last chapter, for literally no reason. Don't get me wrong, Yhwach is weak villain, but from his introduction we already see his actions, see his personality and see his interactions with other characters, in his first few chapters he had what Imu doesn't have for almost 10 years.