Yaosu's training was undoubtedly important otherwise they wouldn't know what situation they would find themselves in. This is why everyone was working so hard because all the efforts were crucial. Moreover, once the Demon Race entered such a state, they would find a way to survive anew without being invaded by anyone. They indeed had such capability.
Those who chose to leave inherently had such courage, but because they had long looked at the problem in completely the wrong way, they even believed that having an army and a ruler was a very unfair method and approach, but this method proved erroneous.
They should have considered changing their perspective because, although their current rulerless state seemed entirely fair, and they were their own masters, they hadn't thought about what would happen when problems arose and no one was able to stand up and take responsibility for everything. They would become like scattered sand, not knowing what to do.
