Why do you care so much about it? If you're going to critique pretty everything in this comic which was NOT INTENDED to be historically accurate (only basic things, but it's a FICTIONAL comic), I don't think you need to know if the gladiator is younger or older
Because messing about with History when something actually historical in nature would serve the same purpose makes very little sense to me.
And because when a man came of age in Rome, he would not have sex with/or allow himself to be penetrated by a masculine male. Ephebophilia; attraction to adolescents from roughly 13-19 years of age; would have been the norm, NOT homosexuality. [Two mature men.] Also, oral sex was looked down on as humiliating and degrading, so there's that as well.
I care because the fetishization of Rome as a whole has led to some rather horrendous misinformation being spread recently. [Gladiator, Spartacus after season 1, and The Centurion being among the worst offenders.]
si no existe se crea que con el morbo que tiene esa época la gente no se resiste xD y con eso que estoy dando historia del arte se apañar una buena ciudad romana por algo borde la pregunta de urbanística romana xD