I think it would have been pretty interesting if 18 convinced Super 17 to change his mind. He was conflicted because of Mu’s programming, but was already fighting against it as he killed Mu.
So let’s say 17 kills Goku, but then has a change of heart. In the Evil Dragons Saga someone else will go with Pan to collect the Dragon Balls, probably Trunks and/or Uub. They can’t defeat the stronger Dragons however, so Vegeta would have to use Bulma’s machine and become a SSJ4 to help them.
I have no idea how they could defeat Yi Xing Long. He’s too powerful and he had regeneration.