The hint is in the title "The Cleanest Race". They consider every other race as inferior. They are nobodies puppet.
If I understood him correctly, Myers was trying to distance their brand of racial superiority from that of the Nazi superman. Superior, yes - but not in terms of intellect or capacity. He called it a moral superiority. That sounds a lot like the Jewish dislike of the Samaritans. They wouldn't even go through Samaritan land because they hated them. So why would NK submit to China since the Chinese are not racial Koreans (like NK, SK and Japan are)? He even pointed out that they emulated the Chinese in many ways.
I guess I'm saying that what he said makes sense, but I am having trouble reconciling some of what he said with current affairs. Your take may be correct, but it doesn't seem to me to line up completely with what Myers was saying. Maybe I'm drawing conclusions incorrectly, but when he makes the distinction between NK and Fascism, NK and Marxism and even NK and Nazi racial superiority, he puts them in a different light than the West is inclined to think about them. Then again, maybe they bristle under the Chinese...