The Navahos weren’t the only Native American code talkers. Lakota people from SouthDakota were also used as code talkers during the war but were not as well known as the Navaho. The last Lakota code talkers, Clarence WolfGuts of the Rosebud Lakota died in 2010.
There were Comanche Code Talkers associated with the 45th Infantry Division in Europe, as well. One spoke to our homeschool association back in Norman, maybe 20 years ago now.
The big difference is the complexity of the Navajo-based code, which went far beyond the use of an almost-unknown language. Speakers of other Native American languages operated more ad-hoc.