scantness vs insufficiency

scantness and insufficiency both are nouns.

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

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

Other hypernyms of scantness include deficiency, inadequacy.

scantness (noun)	insufficiency (noun)
the quality of being meager	lack of an adequate quantity or number
	(pathology) inability of a bodily part or organ to function normally
	a lack of competence