NumPy serves many kinds of users....The challenge: provide ways to guide those users to the parts of the documentation most relevant to them.

I have a thought on how to approach this. We know many of the communities NumPy serves; let's next identify (for ourselves, not the proposal) what each of them needs. It could be as simple as:

Educator

knows...
needs to know...

Researcher

knows...
needs to know..

A table like that would be useful for self-assessment and planning. It helps answer questions like:

Which communities are we most shortchanging right now?
Which communities do we feel most strongly about (our largest base, most disadvantaged, etc.)?
If doc D is our next doc, does it help those communities? Or maybe we want to go round-robin through communities with each new doc.
What assumptions can a writer make about audience background?

We're also then equipped to bring user categories out to a web page and meet the big-tent challenge head-on, with links like:

If you're an educator...
If you're a researcher...

each one taking the user to an Educator, Researcher,..., page containing links to the information they're most likely to want.