I actually always thought Barzini was a composite of Luchesse-Genovese, Tattaglia was Gambino, lol ( just kidding, a little, I actually don't think he was a capable war strategist, or street fighter..)

Corleone was a composite of like, -Profaci (with the olive oil and old world ways, and the compound) Costello ( gambling and political connects), and Bonnano...