leaders vs high command

leaders and high command both are nouns.

Word	Noun	Adjective	Verb	Adverb
leaders	Yes	No	No	No
high command	Yes	No	No	No

As nouns, high command is a hyponym of leaders; that is, high command is a word with a more specific, narrower meaning than leaders:

leaders: the body of people who lead a group
high command: the highest leaders in an organization (e.g. the commander-in-chief and senior officers of the military)

Other hyponyms of leaders include Rome, supreme headquarters.

leaders (noun)	high command (noun)
the body of people who lead a group	the highest leaders in an organization (e.g. the commander-in-chief and senior officers of the military)