>>49107125If we're going by real-life population density, Hokkaido has around 5.2 million in 83,500 sq km so 62 people/sq km. while Kyushu has 13 million people in 37,000 sq km, so around 350 people/sq km. Hokkaido also has the Kushiro Marsh, which is likely the basis for the Great Marsh. So swampy and frigid describes Hokkaido and Sinnoh much more well. Rough, mountainous terrain in contrast to the beaches and warm weather of Kyushu.