In some ways I wonder about the article, because M=10 with a scram-jet is a significant achievement. I think the Russians have done some work in this area, too, and the article does not mention that.
The oriental languages are especially hard for us, because unlike the European languages the alphabet is radically different from ours and often not phonetic. The Koreans several hundred years ago decided to go to a phonetic alphabet. For the longest time the Chinese stayed with a system that has hundreds of symbols.