Oh-kay . Yes - you are right... and yet you are (slightly) wrong.
In this case, while Libre Office is ''content flow'' as opposed to ''page based'' The project is page based - something I was doing, but didn't know exactly how to explain.
thusly;
https://ask.libreoffice.org/en/question/91386/can-i-change-the-page-order-in-writer/
From your question, your document is "page-based". Go to the logical consequence of your choice and store your "pages" as independent documents. To guarantee a common look-and-feel, I'd recommend to design them from a common template.
Then, you create your "synthesis" document (the one meant for printing) as a master document which references all your "page" documents. Read the LO User's guide if you aren't familiar with the concept.
In the master document, the included "pages" can be reordered from the Navigator panel (F5) with "up" and "down" buttons after selecting the "page" you want to move. In essence, it is equivalent to @RGB-es copy-and-paste solution without the risk of incorrectly selecting page content or overwriting other text.
This is basically what I had done in Word...