Just counting the nascent soul cultivators that came from upstream Ethera, there are nine nascent soul cultivators that are more powerful than those three. If Thunder Drake and Lady Evergreen are added, that makes eleven more powerful nascent soul cultivators.
But they didn't send the more powerful nascent soul cultivators to lead the army because they are too powerful for the world. So if those more powerful nascent soul cultivators come with their true bodies, the possibility of being lost in the void is much higher.
Arthur, on the other hand, doesn't have a nascent soul. He only has a golden core, which is similar to the level of existence of the beings that this world can contain. So as long as he can control himself, he won't be immediately ejected from this world.
But this situation means that he will not have any chance to use his minor divine abilities. He is already too strong for this world, so using the Lightning Vessel Sigil technique to fight is out of the question.
