Well you can partially blame the Globe for thatNot mad but the Southern Hemisphere is very under represented in this game.
Inca only. With Buganda and Majapahit on the border.
Southern hemisphere land (not counting Antarctica with no humans) 34 mill km2
Northern hemisphere land 102 mill km2
So you'd expect no more than 25% from the Southern hemisphere anyways
And since most of it was varying degrees of disconnected from the rest of the world (South America only connected to the Americas, Australia with little contact and Southern Africa separated just by distance)... they didn't get remembered as much