headcounter vs questioner

headcounter and questioner both are nouns.

Word	Noun	Adjective	Verb	Adverb
headcounter	Yes	No	No	No
questioner	Yes	No	No	No

As nouns, questioner is a hypernym of headcounter; that is, questioner is a word with a broader meaning than headcounter:

Other hypernyms of headcounter include asker, enquirer, inquirer, querier.

headcounter (noun)	questioner (noun)
someone who conducts surveys of public opinion	someone who asks a question