I wonder what the Godfather films would look like if they'd focussed on other aspects of Michael Corleone's life, apart from having people killed, and the failure of his marriage? I ask because I've just watched the trilogy again, after watching my way though most of the Sopranos episodes over the summer. Some of the things Tony and his family do are just as vile, if not worse; we never see anyone in the Godfather films suffocate an old lady to steal the money under the bed, for instance. Yet all the Soprano family are so much more human, thanks to the more rounded portraits.
Psychologically (I used to work in mental health) it's very well done; you see all the narcissism, the insecurity, the poor relationship skills that the mafiosi have. I wonder how true to life it is? Itr's certainly more believable. But then,, the producers had so many more hours of film to work with.