What if.. all these kids are here because they all have King's Haki/Disposition? And they're trying to distill it. Or something.
They are really strong babies.. giant babies, samurai babies..
--> I have no real reason to think the King's Haki thing.
1. If they have King's Haki, their parents are probably really strong.
2. If their parents are really strong, they wouldn't have gotten tricked so hard by these guys.
Also, I'm sure someone else noticed/thinks this but Law and Buggy's Devil Fruits seem completely complementary. Buggy, within an area, can split himself. Law, within an area, can split others.