literary argument vs sum-up

literary argument and sum-up both are nouns.

Word	Noun	Adjective	Verb	Adverb
literary argument	Yes	No	No	No
sum-up	Yes	No	No	No

As nouns, sum-up is a hypernym of literary argument; that is, sum-up is a word with a broader meaning than literary argument:

literary argument: a summary of the subject or plot of a literary work or play or movie
sum-up: a brief statement that presents the main points in a concise form

Other hypernyms of literary argument include summary.

literary argument (noun)	sum-up (noun)
a summary of the subject or plot of a literary work or play or movie	a brief statement that presents the main points in a concise form