... that will take a lot of renaming
For the uninitiated, a quick and dirty guide to 20th century American military units:
9-10 soldiers = squad
2 or more squads = platoon (~40 soldiers)
2 or more platoons = company (~150 soldiers)
2 or more companies = battalion (~700 soldiers)
2 or more battalions = regiment (or brigade) (~2500 soldiers)
2 or more regiments = division (~10000 - 12000)
2 or more division = corps (20000-40000)
2 or more corps = field army (50000+)
2 or more armies = army group
Depending on the time frame, either "square" or "triangular" is the most common grouping. "Square" = 4 sub units, "triangular" = 3.
A regiment is usually part of a division, a brigade is usually independent. Otherwise, they are roughly equivalent.
A common late WW2 arrangement was 3 or 4 companies to a battalion, 3 battalions to a regiment, and 3 regiments to a division. A corps had 2, 3, or 4 divisions, depending on operational requirements, and an army usually had 2 corps, sometimes more.
All this is very, very broad and intended only to give a general idea of different unit sizes, and can be nit-picked on any given detail. And, of course, it is veering wildly into off-topic territory.
