In regards to naming, I would guess phonetics plays a role.

“Character monikers follow a similar pattern to team names. Consider some of the most popular comic characters of all time: Batman, Wonder Woman, Ms. Marvel and Spider-Man. Eight percent of both male and female characters have gendered names. However, not all gendered names are equal; some fit a “diminutive” category. These are titles that are the younger, or infantilized versions of another name. For example, “girl” is the diminutive version of woman.”