Well... the problem is that there aren't five in either direction. However, I will be looking to offer some serious changes to the raid frame layouts in nUI6 and will offer an option of that sort.
For now, the number progresses always from the top to the bottom and the outside to the inside. So, in a 25 man where there are 12 on each side, it goes like this...
Code:
1 1 1 1 you focus target 4 3 3 3
1 2 2 2 4 4 4 4
2 2 3 3 5 5 5 5
.
Keeping in mind that your unit frame does not show up in the panel. The issue is space and size constraints. Making it all "fit" in the space available.
All of that said, I realize it is not the optimum layout and I will address it in future alternate layouts.