An excellent article with an excellent argument about an excellent film.
I'd like to put a slightly alternative viewpoint to you: The Godfather, viewed in conjunction with The Godfather Part II, is a rather different proposition. In stark contrast to the first film, the rot and corruption has well and truly set in. Compare the colour, vibrancy, and fun of the opening wedding in the first film, to the opening celebration in the second. It's darker, more bitter, and far less attractive. The cinematography is sharper and colder. Throughout the second film, the argument that all Michael does is for the good of his family is less convincing, and I don't think we are meant to be convinced by it. I think that Part II in many ways serves either as a corrective or completion of Part I. Both films are individually superb on their own merits, I hasten to add (I'm still trying to find a good angle to write a piece on them for Medium). But in terms of the argument you are making here, I do think your point applies far more to Part I than Part II.