A side note before I get started: I think that a lot of kids at that age have the teachers=menancing overlord complex at that age. Most kids will either bond strongly with a teacher or absolutely hate them. So maybe it would depend on student/teacher relationships.
Now, Happy Scrappy Hero Pup:
Kids can be strong. My mom works at a school where they have behaviour disorder programs and some times those kids go into places where they can not be brought back for some time, where they are so out of control they have to be physically restrained. These are your average strength and size kids who just so happen to be quarky. Anyways, it sometimes takes up to three adults to restrain them. Something to consider.
Some kids are not quite aware of death at that age as adults are. With violence and death on video games, TV, the movies, and other outlets some kids do not quite get the importance of death. Sure, some of the more mature or older would, but a lot of kindergarteners wouldn’t think of Jennies death as anything more than you being a big mean poo head. They may even think of it as funny (I think of it as funny and I am a little past being that age!).
[Those two I stated above are to add unpredicability to the kids in the situation.]
Now, my direct retort: I think that is a great age to brainwash kids. You could tell them just about anything and they would believe it. Sure, this could work in your favor, but not if it worked in the kids favor first. I think you could brainwash kids to believe something like: “The teachers are using kids for cafeteria food. First, they try to bribe you so that you will be their friends. Then, when you least expect it, they drug you and give the remains to the cooks which turn it into lunch. If we tell our parents they won’t believe us. We have to stop them before they get us!” That may sound crazy to you but believe me there are ways to prove it to kids. If I was a kid aware of this assualt I would gladly knock the force down to 399 just to prove a point. A carefully placed arm under a freezer door, a toe in someones chilly… they would believe it. Then, whenever you would bribe them, they may or may not attack. They would probably be scared, actually. That is when someone like me in that age would yell “you killed our friends and you used it for nachos and chilli!” which would lead to a huge yelling fest. I am sure that if this sceneario allows children killing adults and adults killing children, throwing a chair at a teacher would lead into a chain reaction of hurling objects.
That is honestly something I would think about at that age. I read many, many, many books.
You could train them to even be little guerillas. How to disapear in ceiling tiles, how to use tables and desks for shields, how to help your brother and fight beside him. I think it could very easily be titled in the kid’s direction.
I just thought of something though: are we assuming time to train/brain wash? If it was a sudden uprising adults could very easily crush a bunch of kids. I really doubt kids would attack in the first place if they were not trained to do so. If, however, we assume this fight happens after a duration of a school year or less, and that the kids would be willing to fight to draw blood and the teachers the same, I still hold that it would be children all the way.