Ruoxing wasn't asking for this fro himself though. No. He was doing so for his mother, because of the King chooses to punish him for the heinous crimes he has committed, he could annihilate every person related to him.
So he needed to do this to prevent the King from punishing his mother for his crimes. Hence why he needs Lui to tell the two guys to let him meet with Caishen. But not at their Camp.
He could've used his position to call the older man to meet with him alright, but that would not make Caishen to trust his intentions.
But now that Lui knows that he was aware of everything and yet did not do anything to him, maybe he would believe that he was serious with his intentions?
Having his mom out of Pingheng's hold and giving him his freedom was very important to Ruoxing, so he needed this new plan of his to work.
Hence why he is not using his position to force Caishen's hands by ordering him to come.
