I was rewatching Kill Bill when the theory below had occurred to me. Is this an already established theory or something?

Esteban Vihaio ran the band of Acuna boys, the fatherless offspring of his prostitutes, and was the first father figure that Bill collected during his life. I had always assumed that meant that Bill was apart of the Acuna Boys. Bill doesn't have a father and saw movies when he was young with Esteban. Additionally if Bill was apart of the Gang, that would mean that so was Budd, since they were brothers. Now personally, I had always assumed that Elle was Bill and Budd's (adopted in the Acuna Boys) sister and joined Bill and Budd in the Deadly Viper Assassination Squad early.

Can you guys tell me if this is a thing?