[quote=@Ryuzaki]
Radiant Garden is the KH2 equivalent of Hollow bastion so would it be generally chaotic or what? They [i]are[/i] the same world...
[/quote]

Let's pull some fanon, and say they are different. Hollow Bastion is Ansem's hideaway in this story, but Radiant Garden would be a good base for the Keybladers to use... so yeah, different but similar worlds. Perhaps an aftereffect of Ansem's gaining the power of Kingdom Hearts.