assortment vs grouping

assortment and grouping both are nouns.

Word	Noun	Adjective	Verb	Adverb
assortment	Yes	No	No	No
grouping	Yes	No	No	No

As nouns, grouping is a hypernym of assortment; that is, grouping is a word with a broader meaning than assortment:

assortment: the act of distributing things into classes or categories of the same type
grouping: the activity of putting things together in groups

assortment (noun)	grouping (noun)
the act of distributing things into classes or categories of the same type	any number of entities (members) considered as a unit
a collection containing a variety of sorts of things	the activity of putting things together in groups
	a system for classifying things into groups