cattleman vs cowpuncher

cattleman and cowpuncher both are nouns.

Word	Noun	Adjective	Verb	Adverb
cattleman	Yes	No	No	No
cowpuncher	Yes	No	No	No

As nouns, cowpuncher is a hypernym of cattleman; that is, cowpuncher is a word with a broader meaning than cattleman:

cattleman: a male hired hand who tends cattle and performs other duties on horseback
cowpuncher: a hired hand who tends cattle and performs other duties on horseback

Other hypernyms of cattleman include cowhand, cowherd, cowpoke, puncher, adult male, man.

cattleman (noun)	cowpuncher (noun)
a man who raises (or tends) cattle	a hired hand who tends cattle and performs other duties on horseback
a male hired hand who tends cattle and performs other duties on horseback