I’m under no illusion that the state of my tactical training (read: none) is somehow sufficient to accomplish a task like that

Tactical training can be improved with some time and effort.

And I highly recommend doing it. Because in the coming turmoil, it will be useful for a lot more than just vigilante justice.

(And 'tactical' doesn't just mean 'gun'. Even if you can't currently own a gun for legal or mental health/safety reasons, you can still train. Figure out what self defense tools you are allowed/willing to use. Get them. Train on how to use them. Exercise -- weightlifting, cardio, agility. (At least be good at running away!) Take some first aid courses, then maybe even graduate to field medic courses if you can find them. Acquire and learn how to use methods of secure communication that don't depend on the internet and cell networks. Build a 'go bag' with all the essentials you need to survive for 2 weeks, which can be grabbed at a moment's notice without taking time to pack. Spend some time outdoors, familiarizing yourself with the local area and building up hiking/wilderness skills. Build a secret room in your house where you could hide persecuted people from the authorities. Learn how to build and fly drones. Learn the basics of cybersecurity and maybe even develop some hacking skills. Learn physical pen-testing skills; learn how to infiltrate enemy facilities. Familiarize yourself with likely threats -- learn to identify the enemy and their equipment, especially when they're trying to be covert; learn what you can about their strategy and tactics. If possible, identify weak points and plan ways to exploit them. All of those things can be done without ever even touching a gun.)