What is your proof that said above statement is true?
Do you hold that it is true because the RCC says so?
I could quote you Peter Abelard's Sic et Non.
As a matter of fact the Catholic Church is the Body of Christ. And it includes everyone who has trusted Christ as His SAvior in this age & has been Spirit baptized into the Church. The Catholic Church is not the papal organization now called the RCC.
Now the Catholic Church, being composed of imperfect humans who see through a glass darkly (not yet face to face), the members of the Church have always disagreed on doctrine, though we hold the fundamentals. There are amils, premils, post mils, pretribbers, and persons who eat Post Toasties. Some hold to baby sprinkling, others to immersion of believers who know what they are doing. So your claim is bogus. Any claim that Aquinas & Augustine taught the same, is bogus.
Only in a cult is there nearly pure doctrinal uniformity as imposed from the leader(s) of the group.
I think that you believe whatever the RCC says just because the RCC says so. That is your faulty epistemology; reasoning in a circle. The RCC has no proof for its peculiar doctrines other than the RCC says so.
It could be shown that the RCC has not been systematically consistent in its doctrinal statements. And if your refutation is that the RCC says it has been consistent, therefore it has been consistent, that circular argument is a logical Fallacy.