The latter definition does not draw a line between brigade and regiment, though. Brigades tend to be combined arms, whereas regiments tend to be one-branch formations.


Infantry should be highly agile, a 2 km cross-country run with equipment should be possible at almost any time (I certainly would need two months of exercise till I reached that fitness level).
Not the least for this requirement, I dislike the idea that infantry teams always need to have heavy AT munitions.
I'd rather prefer to have multiple TO&E per team; and a Plt base / cache / carrier vehicle with the temporarily unnecessary equipment.