I think you understand me correctly. The thing is I don't want to hardcode an include directly in a template, because the project features a common group of sections, from which some or all will be repeated across many pages.
It could be worked around either by creating multiple templates with each combination (super-ugly) or by giving each section an option to toggle it on or off, which is less ugly, but still not very flexible or future-proof.
Is there a way to somehow cheat the system so that content generated by using the editor's pagelist/filelist blocks also shows, when the page is included by another pagelist/filelist block?