scantiness vs insufficiency

scantiness and insufficiency both are nouns.

Word	Noun	Adjective	Verb	Adverb
scantiness	Yes	No	No	No
insufficiency	Yes	No	No	No

As nouns, insufficiency is a hypernym of scantiness; that is, insufficiency is a word with a broader meaning than scantiness:

Other hypernyms of scantiness include deficiency, inadequacy.

scantiness (noun)	insufficiency (noun)
the quality of being meager	lack of an adequate quantity or number
Of a garment, the property of being very small, light, or revealing.	(pathology) inability of a bodily part or organ to function normally
	a lack of competence