TB I think it is as simple as this: The intelligence the Corleones had was that the Tattaglias were using their money to front Sollozzo in the drug business. In other words it was an expansion of their enterprise, and they needed the Corleone political support to get this done. In the scene at Genco Vito asks what percentage do the Tattaglias get and Sollozzo looks at Tom and says "te salute" and then says he's take care of the Tattaglias from his share.

When Vito calls Tattaglia a "pimp" it is from the perspective that he never could have out fought Santino, not that Tattaglia was a poor businessman and could not make money.

Perhaps the bigger issue here is why didn't Vito ask Sollozzo, "What about the other families? Are they behind you? Do you think Barzini, Cuneo, and Stracci are going to sit back and watch you make a killing without wetting their beaks too?
Perhaps we should get the whole commission together before we decide on this drug business." This would have bought the Corleones time to build some muscle, it would have kept Luca alive, and it would have forced Barzini's hand.

But as we know, "The Don (rest in peace) was slippin."


"Io sono stanco, sono imbigliato, and I wan't everyone here to know, there ain't gonna be no trouble from me..Don Corleone..Cicc' a port!"

"I stood in the courtroom like a fool."

"I am Constanza: Lord of the idiots."