The convention of hyphen between superheroes' name (Spider-man vs. Ironman)

Chris Ware has a character called Super-Man, who is superficially similar to DC’s Superman, but is unrelentingly more of a dick. See: Fantagraphics’ Acme Comics and Stories

(bolding mine)
Are you saying you would write “Xmen”, or “Xfactor”? Those just look bizarre to me.

Ka-Zar
Nite-Owl
Dr. Mid-Nite

Shouldn’t that be Spinnemensch?