Not a hospital worker, but here’s my suggestion. The moment a threat or threatening behavior (eg getting 3 inches from someone’s face) comes out, they should be banned, full stop. Even if you kinda think they are full of shit and won’t do anything, someone else might feel threatened and that shit needs to be nipped in the bud. Prior to that if they are just raising their voices or otherwise being loud and obnoxious, just start talking slower and more deliberately. Never raise your voice. Just keep to the dullest, most monotonous tone and cadence you can manage. Think Ben Stein going “Bueller?” Never explain reasoning beyond “that’s the rules” or “patient safety” or otherwise vague and void of nuance.

If you see a colleague in those situations, make your presence known. Follow the same guidelines (except if you hear a threat, before engaging you can call security/cops without alerting them). Generally don’t undermine anything a colleague says unless it’s illegal or unsafe. For instance if they say “that’s the rules” but it’s not actually the rules, let that stand. The aggressors would use that to try to divide you and your colleagues and continue to argue/escalate.