Why must those forces go out of their way to stop Zhou Tian's expansion?
The answer lies in the bit of power they hold in their hands. If it weren't for that bit of autonomy, there would be no need for the leaders of those forces to fight Zhou Tian to such an extent. After all, Zhou Tian's strength is evident, and with the way they are fighting now, it is a dangerous venture. If they were defeated by Zhou Tian, they would face the defeat of perishing from the world. Generally speaking, if they could co-exist peacefully with Zhou Tian without combat, they would be willing to give up some benefits.
Yet, in the end, those forces still ended up opposing Zhou Tian. The reason for this is simply that Zhou Tian intended to annex them. Once they were annexed by Zhou Tian, the leaders of those forces would find it even harder to surpass Zhou Tian's achievements.
