One has to consider the context of this expression. If this expression were in the context of a gangster/tough guy, this translation would be appropriate.

It's apparently a samurai or crime scene of scenario/novel. Although it's somehow a strong expression, these were(/are) usually used by a middle/upper-ranked man in his group/organization/society not a lower ranked, so he, as a man of pride, shouldn't want to use F words(口出し無用 is an expression for samurai class, not for civilian). Then even after this kind of men got poor/unemployed, still they tended to use this somehow polite expression from a half their habit. Later on after the samurai era, it seemed to become an expression mainly for men of crime/military who wanted to show a strong attitude. Kozo(小僧) for a small monk trainee, was originally used for an altar boy, but as that tradition disappeared, it became an expression for a boy (usually for a lower-ranked).