supernumerary vs role player

supernumerary and role player both are nouns.

Word	Noun	Adjective	Verb	Adverb
supernumerary	Yes	Yes	No	No
role player	Yes	No	No	No

As nouns, role player is a hypernym of supernumerary; that is, role player is a word with a broader meaning than supernumerary:

Other hypernyms of supernumerary include actor, histrion, player, thespian.

supernumerary (noun)	role player (noun)
a minor actor in crowd scenes	a theatrical performer
a person serving no apparent function	a person who makes deceitful pretenses

supernumerary (adjective)	role player (adjective)
more than is needed, desired, or required