assemblage vs group action

assemblage and group action both are nouns.

Word	Noun	Adjective	Verb	Adverb
assemblage	Yes	No	No	No
group action	Yes	No	No	No

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

assemblage (noun)	group action (noun)
the social act of assembling	action taken by a group of people
a system of components assembled together for a particular purpose
a group of persons together in one place
several things grouped together or considered as a whole