The article suggests we as a society need to recognize the difference between masculinity, which can be perfectly healthy, and toxic masculinity. Forming a violence gang would seem to be an example of the latter and not the former.
You can form a gang capable of violence without being violent !
In my experience you'd call that something like a neighborhood watch or even a militia. Like during the LA riots, the Korean shop owners banded together to keep their property from getting looted.
Among my relatives are police officers, military veterans, and prison guards...
Those groups theoretically exist within the bounds of the law, which should separate them from someone "forming a gang" and using violence to "do whatever they want." The difference between masculinity and toxic masculinity in those cases is a lack of empathy and a lack of respect for societal boundaries or rules of engagement.