If the goal is - to say - to save characters like Alia or Sonia for the greater deepeste darkness inferno underworld planet whatever, characters like Souma and Eden will have their word to say.
And from that point of view, I don't see why you don't consider Yuna as complete as well
Ah, I know, you are a Yuna otaku
Besides, did Asgard, Poseidon or Hades chapters all brought something to the original Bronzes 5?
Shiryu and Hyouga didn't win anything as characters during the Hades, for example...
So I think it's a safe bet that all the Kouga team will be back.