pagetree macro: need the option to sort child pages by arbitrary order

I'm not sure what to call this type of sorting. So for now, I'll call it arbitrary.

It would be nice if the sort option for the pagetree macro allowed for arbitrary sorting. Normally, I would just number each page (which is a tedious process), but when exporting a space with the Documentation theme, it automatically adds the numbers at the beginning of each page.

For example, I have created the following child pages in the given order:

Prerequisites
Tools & Functions
PSL
Analytic Skills

Without numbering these, Analytic Skills ends up at the beginning.