He plays U14. They’re taught about being aggressive and physical, getting their body between man and ball, how to nudge an attacker off balance before challenging for a high ball. That sort of thing. But I can’t imagine any coach teaching up and coming centre backs that every time they come out of the defensive line they either win the ball or clatter someone. Dunno about stone tablets but that seems like stone age football! You don’t see it in top flight football either. Very occasionally a CB who gets it badly wrong will wipe someone out as an absolute last resort but it’s an infrequent occurrence. Not unless Harry Maguire is having one of his increasingly frequent shockers anyway.