The major benefit/challenge of being a military kid that moved every 2-3y is that you make friends really fast and resocialize very easily. This also means you don't have any roots. My example is often that my friends in high school were friends since kindergarten, something I have no frame of reference for. It probably only hurt in high school for sports and clique based activities.

For going from highschool to college there is almost zero negative, since it's the nth time you've moved and had to rebuild a social structure.

Consider the number of total school changes for an average domestic student is 3. K-5, 6-8, 9-12, and in those cases they keep their friend groups.