I have a problem with the whole " All regions happened at the same time" Theroy. Oak was living in kanto, but he later moves to sinnoh to live there forever basically. (he lives in eterna city) So Gen I would have to have ended. But since Gen I ended basically GenIII ended too.
And another thing, Gen II was placed after Gen I, because if you remember after you beat the Jhoto league you can battle the kanto region where everything basically changed. (Seafoam Isle is melted to a small one room cave where blaine is leader, cinnabar is destroyed, Koga's student takes over the poison-type gym, etc).
And since obviously Gen IIII (assuming pokebeach's info is correct), is after Gen I/III we know we could very well be in the same time-region as Jhoto, which IMO just provokes the whole "G/S/C remake" theory even stronger. But IIRC Oak was living in Kanto that gen. But I could be wrong. All I remember from Oak was when he gives me the pokemon egg to give to elm to inspect lol.
And another thing, Gen II was placed after Gen I, because if you remember after you beat the Jhoto league you can battle the kanto region where everything basically changed. (Seafoam Isle is melted to a small one room cave where blaine is leader, cinnabar is destroyed, Koga's student takes over the poison-type gym, etc).
And since obviously Gen IIII (assuming pokebeach's info is correct), is after Gen I/III we know we could very well be in the same time-region as Jhoto, which IMO just provokes the whole "G/S/C remake" theory even stronger. But IIRC Oak was living in Kanto that gen. But I could be wrong. All I remember from Oak was when he gives me the pokemon egg to give to elm to inspect lol.