On that line of thought,
Maybe the Trait
Well Oiled Machine
If all units are from the same Branch of Service from the Same Country, will be able to add 1 to the Setup and Deployment rolls.
This shows that a force made up of differing groups has a slight disadvantage, be it in culture clashes, lang, or just the Acronomicon not being 100% the same.
Only a slight disadvantage as the force has trained at some level together, if it was an adhoc scenario say British & USMC, banding together against a large MEA force, then perhaps in that case another option would be used.
Perhaps, MEA forces pick a table edge, then the USMC & British forces setup on the other, then the MEA chooses to move 1st or have the other side go.
You could make it worse, but that should be a fair atvantage for a game.
Lee