I don’t understand the reasoning behind charging people differently because of their age.
It's like charging someone who has sex with a 9 year old with rape. The 9 year old lacks the ability to consent, due to incomplete brain development, poor decision making skills, inability to foresee long term consequences due to simple lack of experience, and is easily manipulated.
A sufficiently immature person simply cannot fathom the immorality and illegality of an action.
Too bad one of those people has access to The Football, but that's another story, the DOJ has already ruled that he's not competent to stand trial...