Thanks for the additional information about the lack of marriage prospects for a Savoy in 1867. By forcing Italian unification, Vittorio Emanuele II actually endangered the future of the House of Savoy.

The good influence that Marina has always been on Vittorio Emanuele (IV) was noted very early in their relationship. I think that in hindsight Umberto II could not have chosen a better wife for his son. She has always acted with great dignity. The problems that VE has experienced are largely of his own doing.