Interesting and informative, as always. Just to fill in:
Marius is well used in South
Africa, mostly by Afrikaans families whose naming traditions to back to the Netherlands and
France. We also have quite a large Portuguese population, but very few at all from Spanish-speaking countries. Spain mostly colonised South
America, and Angola and Mozambique are Portuguese. Some Portuguese South Africans relocated from Portugal itself and the island of Madeira. I don't remember ever having met a
Mario. My husband's cousin named her son
Marius, but because she liked it, not for any reasons connected with language or family heritage.
Another name that occurs quite often here is
Marinus. I've known more
Marinus people than
Marina people, for whatever reason. I like it very much; I also like
Marius, but
Marinus pleases me more.