The novel explains that Vito kept Clemenza close to him, "on a short leash," while Tessio was given much more leeway. He kept the two apart, the better to prevent them from plotting against him. And it was to Vito's advantage for people to think that Tessio was an independent operator--the better to make them believe Vito wasn't as strong as he was.

At the time of Vito's shooting, Puzo describes Tessio as "the safety-valve caporegime [whatever that means] in Brooklyn."