The only equating I did was to point out that either way you're stuck having to align with a group of people willing and ready to commit lethal violence with lethal weapons.

Use whatever words you want but I think that's clearly violent and it's clearly a gang, which by definition is "a group of persons working together" or even more specifically, "a group of persons working to unlawful or antisocial ends". In this case the newly formed gang is certainly unlawful.

I'm not sure that it's certainly unlawful to defend yourself against gang violence, but I'm not a Mexican lawyer. It's such an odd thing to say that people defending their homes are now a gang because they fight back against the cartel.