Yeah, I'm going mad in my old age. I have 12 rank headicons precached, but there are actually only 6 ranks. It's just that the allies have their team icon as well, and so do the axis:
Allies:
Axis:
As you can see, I tried to replicate COD4's placings of the rank icons instead of the massive rank icon above the head like they did in United Offensive. So, I need 6 headicons for the allies to get the 6 rank icons on, and 6 headicons for axis, although they show the same 6 rank icons as the allies. If I used the United Offensive method and had the big rank icons above the head, I would only have needed 6 headicons, and used the same 6 for both teams.