Hit or miss, frankly. The bigger the area with a larger tax base, the more police it can afford. It can also afford more money in the budget for training which includes things like paying officers for their time to train. Smaller towns and sheriff's departments usually barely run enough people to keep patrol mostly filled, and usually have next to no money or time for training. If your kid doesn't go to that school, then you probably don't know it. Even then, do it know it inside and out? Every nook and cranny?
Rural/small town officers are also usually working one or two extra part time jobs, mowing lawns on the side, etc. to help keep the lights on. And that says nothing about the politics of police training at a school. There's still a lot of educators, school administrators, parents and politicians that don't want us doing that kind of stuff on the regular. Especially not with kids around.
I don't have good answers, man. I wish I did. It's a mix of all of that. Part of me wants to charge in and stop the threat without heed for my own safety, but there are other parts of me that know I need to be careful and proceed as trained. Namely, the parts of me called "husband" and "father."
Maybe, maybe not. Before I attempt to disabuse you (cordially) of some of your misconceptions, though, what is your definition of "militarized"? Be specific.
Not knowing the layout drastically increases the time it takes to clear a structure. Every new door is a brand new thing. You might pop into a broom closet, or it might be a 2,400 sq. ft. cubicle space with a dozen other doors branching off of it. Having foreknowledge of even a general layout will give you a heads up on what doors you can breach without equipment, where the bad guy and others present might be, etc.
Things have appeared to be straight forward so far, but that doesn't mean they will be the day you have to do it. It was more meant to show how a video of them "charging" the shooter is still far slower and more methodical than people typically envision. I'd like to blame movies and TV shows, but really it's a general lack of understanding and perspective from not having done CQB at all. In one of the VirTra active shooter scenarios we ended up having something like 8 or 9 shooters at one school. It kind of felt like a game of Doom by the end of it, but I realized in retrospect where they were going with it. If you are too used to there being one shooter, then you're subjecting yourself to a lot of risk by always making that assumption.