Sectors Card Interactions & Rough Wireframes

Today, I've been trying to figure out the best way to display a clients sectors on their homepage.

Some of the sectors have sub-sectors, some don't. When you hover over a sector, if it has any the sub-sectors will display. Clicking on a sector without any sub-sectors will link to the page, clicking on a sub-sector will link to the appropriate page.

In the attachment, you can find my quick brainstorms on the whiteboard trying to figure out the best approach.