Thanks, gave that a go and it doesn’t seem to make much difference. Using 12 put’s it right below all the home page widgets.
Do I need to set the priority on other elements that are being displayed in that area? I had a quick look in functions.php and couldn’t really see where I would add the priority for the slider itself.
The main goal for moving the primary navigation below the slider is so the the drop downs menu items are not hidden. Not using a menu in the “Header Right” widget on this occasion.