Yes,
Mato and
Ranko are quite old-fashioned.
My grandfather was
Mato and I do know one who's 24, but he was also named after his grandfather. In my generation
Matija and
Mateo were used and nowadays
Matej is the most popular.
Ranko fits in with other –ko names which were common in the 1950s and 60s and are dated now (
Branko,
Mirko,
Slavko,
Darko, etc.).
Marko is the only –ko name still very popular, but then all Evangelists' names are.