As fuzzy as human race categorization is, which of the following 3 systems are valid for population specific boxes?

Clades, clines, clusters. Is only one system valid? Two? All three? None at all?

I've heard and seen scientists debate this since around the early 2000s with conflicting answers so I'm really curious to hear what's the most appropriate take on this topic.

And let me disclaim that obviously human populations are fuzzy categories to begin with.