Earlier quoted context omitted.
It seems to be very hard to distinguish between bullying and rough play. Rough play is a developmental requirement (particularly for young boys) across the hominoid clade (and likely wider). Being denied it also has real and lifelong consequences. For further reading, Frans de Waal has done a lot of work in this area. Educational policy informed by this research usually looks not to intervene in physical conflict bet…
An interesting approach I read - I think it was a novel, honestly, but may have been an autobiography - was that fights were not just tolerated but sanctioned, with one big proviso: In the gym, with boxing gloves and headgear on, and fists only. Going down or taking a knee ends the fight. Let 'em work out the tension, but with very minimal chance of hurting anything.
I went to a strict religious school and a kid who bullied me over years pushed me too far one day and I started after him, got maybe one kick to his leg in. Teachers stopped me immediately, but never did the same for the years of verbal abuse mocking me for my weight though. I ended up getting spanked by the principal with a thick wooden paddle in front of my teacher that day. This was the mid to late 90s. I heard once the kid who bullied me is in prison now.