The movie fails to explore the complexity of the code talkers and more importantly the code itself which wasnt all navajo based. And that was why the code really worked. They even used many dialects derived from northen spain's basque and cherokee, choctaw etc. etc.
shareOne wonders why facts such as yours were not considered. This movie had the potential to be great. The only thing lacking was adequate writing, directing and acting.
shareI've met two Navajo Code Talkers who were brothers. They told me the code worked mainly because the Japanese had no knowledge of the Navajo language, in fact they didn't even know such a language existed. The fact that Navajo didn't exist as a written language and had no alphabet made it impossible for the Japanese learn it.
You're right, they did add some small but significant twists, such that it wasn't pure Navajo. This was to ensure that the Japanese couldn't kidnap a Navajo to help them figure it out.
I'll take Punctuality