showman vs doer

showman and doer both are nouns.

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

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

Other hypernyms of showman include actor, worker.

showman (noun)	doer (noun)
a sponsor who books and stages public entertainments	a person who acts and gets things done
a person skilled at making effective presentations