And both won Rome as well
Close call IMO
If you feel Nusslein is underrated....Imagine Santana!
Nüsslein is vastly underrated or even unknown while Santana is overrated (like Emerson). Nüsslein was strongest claycourter of the 1930s (9 claycourt majors won) while Santana was never strongest claycourter of the world: Laver, Rosewall and Gimeno were better.