Yeah, but 23% rural pop making up 36% of recruits vs 77% of the pop making up the other 64% means that while yes, there are a lot of rural kids in the military, there are still far more kids from the burbs and cities, and shit, it takes a lot of work to turn any of them into people willing to go "over there" and pull triggers, and when a big part of doing that involves stressing the importance of keeping that shit "over there" to keep folks "back here" safe... asking them to go do the same shit "back here" is a whole other cakewalk.
It's totally possible to train people to do this, for an example: cops get trained to look at people as potential threats WAY THE FUCK too easily, and get told that they're more or less always in a warzone.
This suggests to me that asking dudes and gals a year or two out of boot camp to start running around looking at the civvies they've been training to fight FOR as if they are threats and targets isn't going to result in bloodbaths as quickly as some shitbag like Trump might hope.
Honestly I'd expect a soldier to assess the situation and identify that the aggressors are the guys armored up like a bunch of wannabe operators chasing kids around with tear gas and batons and rubber bullets, so the reflex probably isn't going to be to assume the cops are on the right side when they're actively attacking folks you LITERALLY decided you would risk your life to protect, sight unseen.