Interacting as a substitute teacher in an overseas DOD school with the “brats” may have been a factor behind my wife encouraging me to leave active duty as early as possible. Of course, no substitute teacher ever has it easy taking over a class. I went to college and ROTC with a few “brats” and had no issues with them at that age.
My guess is because they are always having to move and always having to start a new school, they have to fight a lot until they fit in. I always liked army kids. Preacher’s kids are supposed to be brats too.