echelon vs military group

echelon and military group both are nouns.

Word	Noun	Adjective	Verb	Adverb
echelon	Yes	No	No	No
military group	Yes	No	No	No

As nouns, military group is a hypernym of echelon; that is, military group is a word with a broader meaning than echelon:

Other hypernyms of echelon include force, military force, military unit.

echelon (noun)	military group (noun)
a diffraction grating consisting of a pile of plates of equal thickness arranged stepwise with a constant offset	a unit that is part of some military service
a body of troops arranged in a line
status in a society or organization