Way I see it
-it would be a waste for Jinbei and Jack not to fight given they are (so far) the two strongest fishmen in the series
-it would be a waste for Sanji and Queen not to fight given Queen seemingly has a relationship with Judge
-it would be a waste for King and Marco not to at the least clash, given the similarities between the two
-if would also be a waste for Zoro and King not to fight given their respective similarities
So if I was to guess I’d still say it’ll be a clash between King and Marco, but Zoro vs King being the main fight.