army unit vs brigade

army unit and brigade both are nouns.

Word	Noun	Adjective	Verb	Adverb
army unit	Yes	No	No	No
brigade	Yes	No	Yes	No

As nouns, brigade is a hyponym of army unit; that is, brigade is a word with a more specific, narrower meaning than army unit:

army unit: a military unit that is part of an army
brigade: army unit smaller than a division, typically consisting of a small number of battalions

army unit (noun)	brigade (noun)
a military unit that is part of an army	army unit smaller than a division, typically consisting of a small number of battalions

army unit (verb)	brigade (verb)
	form or unite into a brigade