See Word's Numbering Explained by John McGhie, MVP - comprehensive and not pretty (Downloadable pdf file in letter size) - Reading this is vital to anyone attempting to use automatic numbering or bullets in a law office setting or other places where the documents are likely to be reused or heavily edited. See also How to Create a Template with a downloadable template with style-based numbering.
I agree, MS documentation completely fails concerning multilevel lists. Additionally, it is not even close to being intuitive. But more than that, the controls for it are actually ambiguous and misleading. Then too…..there are still bugs in it. To be fair, there is nothing simple about this operation….but still….Microsoft, you've got bzillions of folks and could do this a little better. Whem my multilevel lists start going squirrely on me I usually make sure my active cursor is located in my list and then click >multilevel list>define new multilevel list. I check everything is set the way I want (it usually is) and hit "ok." So that seems to just refresh everything and set the list straight again. I don't know if it actually does define a new one (or how I would ever select it again if I wanted to) but that works best for me until MS fixes it.
Warning  Making even minor changes to an outline numbering scheme won't necessarily change the initial position you've selected in the gallery, but rather may create a new gallery position, overwriting an existing one. Because of this problem, attaching numbering to styles is strongly recommended. This is covered in greater detail later in this chapter and in the chapter on Styles.

Inserting page numbers into your InDesign document is quick and simple. The first thing to realise is that InDesign numbers pages according to the page numbers listed in the Pages Panel (Window > Pages). Unless you want to spend the time manually inserting individual page numbers to override this, you should understand how to define sections in your document (see Step 2, below). numbering