Then why put Kuma and everyone in the Rocket tube in the position they are in now lol?
Soon, something will happen between saturn and Kizaru's friends, Bonney, Kuma, Sento and the punks. (My guess is, some more punk's will get killed maybe while trying to shield kuma and Bonney. Atlas is a big target for this)
And that will force kizaru down from the fence and into the side of his friends.
egghead marines going back to ships wasn't a plan by kizaru. But it is an opportunity that he will utilize later.