Sgt_Kickaxe - 11:38 pm on Sep 2, 2010 (gmt 0)
For every solid article about the primary keyword set it seems you need a couple of checkdown articles covering the lesser sets. This can happen naturally when you write about something more than once so just make sure to link to the primary page from each of the others within the content.
It's best to simply produce content to the point that when you look at such a keyword list you are ranked on page 1-3 for every combination. A solid internal link structure and good SEO practices can get you that far assuming you have a content rich site. When you've reach that point you can begin to sort it out and adjust the pr flow to move specific pages up. Trying to do it too soon results in a wasted effort when you later add content that changes the structure again.
Also, if you're feeling that there is an aspect of a subject that needs expanding, but you've already covered it 3 times for example, don't be afraid to modify/add to an existing article.