It also depends on how strongly clustered the land tends to be - if the land is all going to be continuous then presumably there are more distributions of that

It also depends on how strongly clustered the land tends to be - if the land is all going to be continuous then presumably there are more distributions of that land that are weighted towards a single hemisphere. Suspect there’s something to do with the fractal dimension of the coastlines as well. Agreed - sounds like a rich vein of math.