rainmaker vs medicine man

rainmaker and medicine man both are nouns.

Word	Noun	Adjective	Verb	Adverb
rainmaker	Yes	No	No	No
medicine man	Yes	No	No	No

As nouns, medicine man is a hypernym of rainmaker; that is, medicine man is a word with a broader meaning than rainmaker:

rainmaker (noun)	medicine man (noun)
American Indian medicine man who attempt to make it rain	a Native American shaman
executive who is very successful in bringing in business to his company or firm