Regardless of the morality of the African situation, it demonstrates as a basic premise that youngun's are capable of holding their own against adults in combat, at oeast once you factor in extenuating circumstances. Also factor in that the average comic, a sidekick isn't going to be forcibly recruited by the hero to kill folks they know nothing about but are instead volunteers pursuing their own agendas who are hooking up with the hero for protection and vocational education to pursue that agenda.
Personally I think it'd be far more reprehensible just to leave that angry / overly idealistic young person to their own devices rather than to mentor them.