Is there just one "Posette"? And is she the female adult from P4?

Is the female from P5 different or based on Posette? I know at some point they started getting names to compete with Mike and Vickie.... And I've figured out a little of their history (unimesh), I get the asthetics of Hiro and Aiko, but I don't understand why David and Skipper are necessary.

Then there's Eve and Apollo and Glory(?). Who ARE these people? Independents?

While we're at it, does anyone know the whole Poser genealogy? Or a product comparison page? Do they all have different texture mapping? Aren't some compatible? Augh....!

**yes, my computer is tied up rendering and I've nothing better to do...