F 14 suggestion

[Volcano Man]

I don't see why. If they had to intermix then they would of (and in some cases did at 1st Ypres). There is already a command penalty of sorts in that they cannot attach units to each other, so if someone wants to mix them up beyond that, then I don't see a reason to artificially prevent that from happening.

My only guess as to where this is coming from is that someone decided it best to stack a BEF battalion with a French battalion. BEF for the soft attack and French for the assault, but meh, that is one fat target than can be punished by fire quite handsomely.