I have an idea since time ago.
The Theme Sequential by wordpress allows to show child pages content in the parent pages. By default, a page is a page, but if you choose the for the Parent page the Feature grid template, each child page are available in the parent page.
Take a look the page i did create. One parent page with two child pages.
Now, the content of the parent page is in the top, and the child pages are down. Instead of a grid template, imagine a template where each page is a section. Something organice as http://open.books4languages.com/grammara1en/chapter/to-be-affirmative/
In the way I would like to do the content, the most of the work is done automatic because of the metadata. It would be a simple way of creating pages (I hope the next summer I can start to work with that). but for the general use, is much simple and can be done by hand.
We have parts and chapters. We need now sections. Where a section is a child page of a chapter.
The backwards compatible is: if we have a book. All the current pages are chapters. And you can read as now. No issue. But if you write a section of a chapter, that content would be after the content of the chapter.
As we always use the chapters for writing information (I think in the future is the place for the introduction or a short information about the chapter if necesary), the chapters can work as now.
The chapter would show content of the child just if there is a child or more than one for a chapter. If that happe, the child pages (sections) would be afther the parent page and no one would see in the frond end is a combination of pages. Just one long scroll with sections.
I realice that the day I take a look to the wordpress post formats. The formats are not useful for a page/post, as the page is too big and with many different content. But if we do create a tiny entity, we can use each format for each child page and to have a page made by pages (like the feed of twitter if you search for a #). Because a child page can be a picture, a video, a song, text… and the parent page is a combination of all of them.