sticklerism vs rigidness

sticklerism and rigidness both are nouns.

Word	Noun	Adjective	Verb	Adverb
sticklerism	Yes	No	No	No
rigidness	Yes	No	No	No

As nouns, rigidness is a hypernym of sticklerism; that is, rigidness is a word with a broader meaning than sticklerism:

Other hypernyms of sticklerism include inflexibility, rigidity, conscientiousness, painstakingness.

sticklerism (noun)	rigidness (noun)
The behaviour of a stickler; inflexible adherence to rules.	the physical property of being stiff and resisting bending
	the quality of being rigid and rigorously severe