rule of morphology vs morphological rule

rule of morphology and morphological rule both are nouns.

Word	Noun	Adjective	Verb	Adverb
rule of morphology	Yes	No	No	No
morphological rule	Yes	No	No	No

As nouns, rule of morphology and morphological rule are synonyms defined as:

rule of morphology and morphological rule: a linguistic rule for the formation of words

rule of morphology (noun)	morphological rule (noun)
a linguistic rule for the formation of words	a linguistic rule for the formation of words