Subpages of [[Flow]], [[Echo]] and the like must not contain documentation: if you find documentation under them, move it to Manual or Help namespace. (Only a negligible portion of pages should be in breach though.)
Pywikibot is not forced to have everything under one page, that's just a byproduct of the import from Meta. If there is a cluster of non-documentation material on the development process or whatever, it would be useful to collect it under a single place in ns0.
Nemo