Stan wrote:
"Very interesting! I take it the article counts are simple sums of cat and subcats, and don't account for an article appearing in several subcategories?"
Indeed. The number behind each category is the total number of pages in that category and all of its subcategories.
Of course if you add up the pages counts for all level 2 categories you will get a multitude of the total number of articles in Wp, since one category will often appear as node in several branches.
Erik Zachte