New medieval world map

I'm creating new medieval map (1300-1600).
Should I create North American and Australlian tribes? What do You think?

Sure. Make everything necessary to make this map/scenario a different experience from other medieval maps. Ask yourself, what is the cutting-edge of this map in comparison to other medieval/ancient maps?
The territories, units, events, distribution of cities, etc.
World map and "only" 1300x1600? Would be a miniature world. Interesting.

No no, 1300-1600 is time perioid. New units will appear during gameplay (such as units using gunpowder).
I want to make many unique units (this will be hardest part because of game engine).

Oh... cool. Available units from a certain turn onwards. I like it; Sapien has it and it is very entertaining, according to some players.

I already made one based in 1400. I was going to add Australian natives but I decided meh