Heres a Crazy, implausible idea but anyway.
Let's say Japan Get's Beaten/Surenders early, so D Day (Or it's equivilent analouge) gets multiplied by five, with a compsoisiton such as this.
The British, which of course includes English, Scots, Welsh and Irish, With colonial forces from East, West and Centeral Africa, India, Nepal, Bhutan, Tibet, Afghanistan, Burma, Malaya, Yemen and the Trucil states aswell as contingents from British protectorates such as Eqypt, Iraq, Persia, Trasjordon and Palestine.
Then, you have contingents from the British Dominions, in which case you have Australia with Aborigionies and New Guineans, New Zealanders with Maori and Polynesians, South Africa with Afrikanners, Zulus, Xhoxa ETC, Canadians with Qubebecouis and Aborigionies as well as normal White Anglo Saxon Protestants.
Next You have the US, which includes Whites from all Backgrounds, Blacks Native American Indians, Hawaiians, Philipinos, Japanese Americans and Hispanics. Added to this might be contingents from South American Nations attached to the US Army, like the Brazilians and Mexicans from OTL.
Next you of course have the Various Free Contingents from Occupied European Nations like France (which would include West Africans, Algerians, Morrocans, Tunisians, lebenese and even Vietnamese, Cambodians and Laotians), Poland, Czecheslovakia, Norway, Denmark, Yugoslavia, Belgium and the Netherlands.
From Now it gets Harder, so maybe we can add a Chinese contingent in there which would include Han, Manchus and Mongolians, Ethipoians and maybe a Jewish Contingent for good measure.
What do you think?