Paul is a man's name. Will is dating a girl named Paul? WTF?

It's not uncommon for names to cross gender norms, particularly from male to female. Names like "Leslie" or "Sidney" used to be considered men's names, but are now thought of as women's. There's a woman I work with named James, and dog help you if you ever call her "Jamie."

Cultures are living things, not monolithic blocks. Details and common uses change over time.