Exactly what I was thinking, leave Good and Evil out. Then your PCs who likely try to be good people can sometimes work for Law, sometimes for Chaos.
I can see the Neutral philosophy being very popular among people without power, which is also interesting.
Law has two faces, benevolent and tyrannical, but it feels like Chaos only gets its faces based on which kind of Law it is opposing. Maybe Chaos can be interested either in strengthening the weak or taking down the powerful. Neutral then does not get a duality because it is Neutral.
And then you get to consider if Outsiders exist and how they act... this is a simple base that can go many ways. I like it.