efficiency engineer vs efficiency expert

efficiency engineer and efficiency expert both are nouns.

Word	Noun	Adjective	Verb	Adverb
efficiency engineer	Yes	No	No	No
efficiency expert	Yes	No	No	No

As nouns, efficiency engineer and efficiency expert are synonyms defined as:

efficiency engineer and efficiency expert: an expert in increasing the efficient use of machines and personnel

efficiency engineer (noun)	efficiency expert (noun)
an expert in increasing the efficient use of machines and personnel	an expert in increasing the efficient use of machines and personnel