Based on what you asked...
You can import the content from other documents by using IncludeText fields or importing via VBA. I would assume you would want to develop a userform that presents a list of available chunks for inclusion and you could then choose from this list and re-arrange selected items into an acceptable order.

As an alternative way of thinking about the problem...
Normally when I do jobs like this, I actually prefer to place all the individual components into a single template, storing each one as a building block. Then I build a userform which reads the list of available building blocks and allows me to select them for inclusion. If you don't have sufficient experience in VBA this may be very difficult but you could choose a no-code alternative - just use the Insert > Quickparts path to bring each piece into the current document.

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Andrew Lockton
Chrysalis Design, Melbourne Australia