Like you said, that list might feel a bit too fine-grained, at least to my uninitiated eyes. Maybe something like:
soldier/personal vehicle
squad/small vehicle
platoon/large vehicle
regiment/small base
army/large base
...to not get too technical?

I mentioned Vincent's Stat Strata in the stat thread. Do you think something like that? A missile launcher might then in itself be a personal stratum weapon, because it doesn't need a squad to operate, with missiles doing squad or even platoon stratum damage, depending on target and missile type?