brushwork vs proficiency

brushwork and proficiency both are nouns.

Word	Noun	Adjective	Verb	Adverb
brushwork	Yes	No	No	No
proficiency	Yes	No	No	No

As nouns, proficiency is a hypernym of brushwork; that is, proficiency is a word with a broader meaning than brushwork:

brushwork: an artist's distinctive technique of applying paint with a brush
proficiency: skillfulness in the command of fundamentals deriving from practice and familiarity

Other hypernyms of brushwork include technique.

brushwork (noun)	proficiency (noun)
an artist's distinctive technique of applying paint with a brush	the quality of having great facility and competence
	skillfulness in the command of fundamentals deriving from practice and familiarity