supernumerary vs doer

supernumerary and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
supernumerary	Yes	Yes	No	No
doer	Yes	No	No	No

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

Other hypernyms of supernumerary include actor, worker.

supernumerary (noun)	doer (noun)
a minor actor in crowd scenes	a person who acts and gets things done
a person serving no apparent function

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