There seems to be 3 default officer portraits. One for each Army where a name isn't allocated in SoWWL_Portraits.xml, unless I'm misreading things.

What controls how this default portrait is allocated to a unit?
Is it merely the OOB portrait entry? Doesn't seem so.
Is it unitglobal? - in SoWGB you could amend cols W & X to point individual units at a particular friendly or enemy GUI, and its associated portraits.I'm struggling to find something similar in SoWWL.
Or another xml file?
I've worked out how to point an OOB_Name entry at a portrait by amending SoWWL_portraits.xml & the OOB.
However, I'm struggling with these defaults. For example I want new entries in unitglobal to use the default French officer portrait but they still use the British default officer portrait (not even the Prussian one) which made me think I needed to tweak unitglobal or the new xml that replaces the friendly GUI facility. However, I'm struggling to locate it.
I assume it's something tucked away in the csvs or more likely MyGUI but rather than stumble around for a few more hours I'd appreciate a steer.
I expect it's something obvious I've missed B)