> You've already conceded that the armed citizenry is no match for the military
That's not what I said. I said the military probably wins numerically. For what it's worth, numerically the civil war should have been over in about 6 months and an entirely lopsided victory by the Union. "Probably" should most certainly to be understand as "the most likely but not certain outcome". The US probably would have won Vietnam if they had continued fighting another decade - would it have been worth it though?
And the time element is part of the issue. It turns out if you show up, massacre of a bunch of unarmed folks in a day or two and then do a halfway decent job of suppressing it, well, Tiananmen square.
In the US, when we've had the military fire on citizens, the response was a bunch of upset, armed citizens said "We'd really like to see due process happen." And then unlike Tiananmen, the perpetrators were arrested and tried in a civilian judicial system because that was less terrible than an armed population getting rather upset.
Remember, this is the whole reason why the founding fathers were pro individual ownership of firearms - they had been the victims of military massacres, military troops being quartered in private houses, and eventually their own government hiring mercenaries to enforce the peace through force. Part of why the British chose to hire foreign mercenaries for swaths of the war instead of use their own troops was because they were concerned about morale and defections. Likewise, the first thing the British wanted to do once things started going south was to lock up all the ammunition and arms so the citizens couldn't put up any trouble.