Think of it more like a union. And armed forces arent necessarily the best vehicle for political change for obvious reasons, but rather they are good for protecting human rights from institutions that want to take them away. For instance, a pro choice militia that would protect a clinic, doctor, or patient from a state agency trying to arrest them and prosecute them. Also, it doesn’t need to end up in a shootout, a lot of military and defense is about hypothesis of conflict and the potential cost that comes with it. Sure, a federal or government institution could wipe the floor with the militia, but would it be worth it monetarily and politically?