What we need to remember, Google is very picky, and even if you submitted all subpages of your website Google will index only part of it at first anyway.
What is more important is to make sure all pages cross-reference each other, so make sure you make good use of main navigation, breadcrumbs, footer links etc. Because this is the main way googlebot will crawl your page.
Personally I had situation where after updating sitemap.xml Google immediately said new link in my sitemap is already indexed (because googlebot indexed it on its own before it was placed in the sitemap.xml).
Conclusion - add as many links you can and don t worry about missing ones. Just make sure you update your sitemap.xml once in a while (or do it programmatically).