Even if Chiatzu overpowers them, and he might, the One Piece characters have been shown able to bare minimum destroy the islands of the world, which are consistently around the size of Australia or more. And then on a high end they're capable of destroying the planet they're standing on, which given there's 20 million islands on the planet and a sizable portion are the size of Australia you can imagine is more than the size of Earth. Not to mention a lot of low end scaling gets One Piece characters to light speed but higher end scaling gets them a lot faster.
But we can't say for certain how strong Chiatzu is, we can even assume he is relative to maybe some Frieza Saga level characters or beyond. Like Android Saga characters, he would still lose because of abilities like Room which can switch souls or split him into pieces, or the Sickness fruit, or poison fruit, or soul fruit, or any number of devil fruits with instant win effects provided you don't have Haki
