I'll be good if they give a little penalty for international corps, more if you add differnt language troops to fight together (for example the 15th Army Group had troops from Canada, Indian, Poland, South Africa, Greece, Brazil and New Zealand, and the supply was more difficult than an all anglo or an all british or american army.
The Canadians, South Africans and New Zealanders would have spoken English. The Indians were part of the British Indian Army and would have either spoken English or had British officers who spoke Hindi or some of the other Indian languages.
The Poles, Brazilians and Greeks would need to find a few people who spoke English or the British and Americans a few people who spoke Polish, Portuguese and Greek. The Greeks were only present in brigade strength so they would have hardly brought the Army Group to a standstill had communication been a problem.
I saw generals create imaginary "masses of manoeuvre" with a crayon and dispose of enemy concentrations, that were on the ground and on the map, with an eraser. Who was I to criticise them, hero as I was of a hundred "Chinagraph wars" of make-believe?