Can humanity be categorized into 16 types?

The theory of temperaments (choleric, phlegmatic, etc.) was even more concentrated. Then there's astrology with its 12 signs. Myers-Briggs has 16 (and there are more to come). How are such typologies developed? Why this number and not more? Couldn't I also classify humanity by the way pizza is eaten, the way people walk, etc.? Or…