WI during WWI & WWII, in addition to the US Army & Marines capitalising on & utilising native American languages for code purposes- a la the Choctaws of the 36th TEXAS Div on the Marne, the renowned US Marine Navaho codetalkers, or the 4th IVY LEAVES Inf Div's Comanches at Utah Beach- other combatants had also utilised such unknown indigenous languages for their own communications code purposes ? WI say the British had used some of the more obscure Indian or African dialects, training up suitable speakers for that cryptography purpose from among their colonial forces, then used em in Africa, the Mideast or Burma ? Likewise, if Commonwealth armies had done the same thing- Canadians with some of their First Nations soldiers from the more obscure tribes, Australians from among their traditional Aborigines (esp from say Arnhemland or other areas where there wasn't as much black-white contact), Kiwis with some of their Maori soldiers ?
(Of course, admittedly there could be potential drawbacks- as illsutrated by 1 novel on the West Africans fighting in Burma during WWII- when the Nigerian soldiers actually try to communicate in each other in Hausa, but on the Jap side is 1 guy who spent time studying in London before the war & picked up some Hausa from Nigerians studying there- but anyhow...)
(Of course, admittedly there could be potential drawbacks- as illsutrated by 1 novel on the West Africans fighting in Burma during WWII- when the Nigerian soldiers actually try to communicate in each other in Hausa, but on the Jap side is 1 guy who spent time studying in London before the war & picked up some Hausa from Nigerians studying there- but anyhow...)