Andy, let us say that we have only 2 main categories: A & B.

Category A has 2 subcategories: A1 & A2; Category B has 4 subcategories: B1, B2, B3 & B4.

Category A has 50 links in total, but when you click on it, there is no link at all - links are in A1: 40 and in A2: 10

Category B has 100 links in total and they all resist under the main category, all 4 subcategories are empty.

Now, the global should display the following:

B: 100 links
A1: 40 links
A2: 10 links

Note that there is no "A: 50 links" because in fact the main category is empty.