If Paolo had not been murdered but Antonio and thier mother had been do you think the two brothers would have started a family in Sicily, or moved to America together? Maybe the Andolini family and Paolo as don with Vito as underboss? I think I can remember hearing that Genco's family were friends with the Andolini's in Sicily so Genco would be consigliere to Paolo? Or they moved to New York worked as low time enforcers to Fanucci? I would think that Paolo was ruthless like Michael so he would rise to be Fanucci's bodyguard and then stab him in the back. Do you think differently?

There is nothing in that scene that suggests that the Andolini family had enough clout to challenge Don Ciccio, best him, and establish a Mafia family. If anything, the scene suggests that they were victims of the kind of vicious violence that the Mafia perpetrated on ordinary peasants in Sicily at that time.