fluency vs smoothness

fluency and smoothness both are nouns.

Word	Noun	Adjective	Verb	Adverb
fluency	Yes	No	No	No
smoothness	Yes	No	No	No

As nouns, fluency and smoothness are synonyms defined as:

Other synonyms of fluency include eloquence.

fluency (noun)	smoothness (noun)
the quality of being facile in speech and writing	a texture without roughness; smooth to the touch
skillfulness in speaking or writing	the quality of having a level and even surface
powerful and effective language	the quality of being free from errors or interruptions
	the quality of being bland and gracious or ingratiating in manner
	powerful and effective language