Olivant, I must respectively disagree with that. While Vito was incapacitated, Sonny actually was the acting Don. Even his own father aknowledged that :
"I thought -- Santino was a bad Don, rest in peace."
Don Cardi
On the other hand, as the novel states, Sonny recognized the Corleone weaknesses one of which was the eroded quality of the Capos. But, only the Don could replace them and Sonny was not the Don.
Ahhh, but we are discussing what the average person knows from the film, and not the novel.
Ok, Ok, Touche!
Don Cardi
Don Cardi
Five - ten years from now, they're gonna wish there was American Cosa Nostra. Five - ten years from now, they're gonna miss John Gotti.