Pages operate under a hierarchy, if a page is a child of another page, the url reflects the hierarchy of that relationship..
With pages, both %postname% and %post_id% are treated the same, pages are not listed using their ID but they’re name.
The same is true for any permalink structure in regard to pages, aside from default.
Pages are intended to behave like static pages, so where as a regular php site may have a home url and page urls like the following..
example.com
example.com/page1.php
example.com/page2.php
WordPress would emulate that behaviour with the following …
example.com
example.com/page1
example.com/page2
Subpages are an equivalent of example.com/folder/page.php … again this is just an emulation of using static pages on a PHP based website i believe.
ID’s really only apply to archived content, such as posts.
Or at the least, that is my understanding…
Following recent discussion on permalink performance, if you have any intention of using alot of pages on your site, i’d recommend using one of the provided options for permalinks.. in any case, page permalinks should behave the same way under either settings.
I did do a few permalink tests to check behaviour, so what’s said above is based on my brief testing and my existing experience using WP, but it’s by no means a definitive answer (i don’t write the code personally).
If you feel you have a particular need for pages, perhaps you could outline your reasoning for choosing to use pages, then maybe myself or another member can offer an alternative for organising your content in a way that will provide nicer and better suited URLs.
I’m off shortly (uk time), so if you don’t get another response back quite so switftly it’s not because i’m not following the thread… ??