We are saying the same thing. Yes, you should execute the elements correctly. But how they are put together in combinations is just somebody's suggested choreography. USISTD, DVIDA, Fred Astaire, and Arthur Murray (obviously I'm talking about American Style; in International Style the syllabus mostly consists of elements--a Three Step is just that, not a combination) may all have a Tango pattern that incorporates certain elements--possibly with some variation. Those patterns are close to one another but not identical. Is one more "right" than another? Possibly yes for a competition that requires a specific syllabus, but not in social dancing.