>>46436256I think that's likely based on the level of technology, but at the same time they fuck around with that a lot in Pokemon so I wouldn't be surprised if it was 3,000 years ago like everything else. And even then, if the technology is there so is the possibility of general global trade.
PokeJapan being more open is the main difference here. In real life they stayed far away from Hokkaido until the 19th century when it really wasn't that far away.