The Family is a team. Its members' business is delegated. Discipline is enforced as misbehaviour endangers the entire family, not just the perpetrator. The woman, a necessary evil, is treated as property so as to limit the rotation of cadres.
Roger Sartet (played by Alain Delon) is a loner. He does his own thinking. He is good at it, given he has managed to live to thirty-five. Honouring verbal agreements with strangers means more to him than to the Sicilian Family; the Family deals with strangers less often than the loner does and hence relies less on external reputation.
M. Sartet is an idealist: in his dress, his confidence in his ability to tell who can be trusted and for how long, his belief that the trusted shall be trustworthy---and his calculation that they probably will not be such. His shooting makes up for the paucity of his talking. He is at his best, however, when doing neither.