Most likely the bullies are members of the school's football team, hence the protection afforded to them.
So option three, but targeting the Achilles heel tendon or other sport-critical tendon/muscle, is a great option, in my opinion.
Clearly the school has a bullying problem, and a control problem. It's a sick, diseased school run by weak people, and teachers too afraid to do their job to protect students from bullies who are on the school football team. This is something that requires state intervention, I presume the state has school inspection bodies, and the ability to enact punishments? I would suggest a ban in intra-school sporting competition for a couple of years until the school's curriculum has moved back towards education.
Indeed, I think that US school sports is really weirdly venerated. I'd split the two up, schools can have basic sport, but clubs, etc, should be run outside of the school, maybe with loose affiliation, but having no influence on the school's central reason for existence - education.