Check the maps for North America:
And then compare it with the maps of South America:
You can even see that Amazonia could fit a least 2 or 3 more maps: the map as it is right now, calling it deep amazon; the amazon delta with many river mouths; a black forest map in the western zone and a mountainous jungle map in the space north of Pampas Sierra. Andes, Araucania and Pampas Sierra too could be divided, just as north america has Alaska and Yukon, Rockies and Cascada Range, California and Baja California, Great Plains and Ozarks, New England and Plymouth. Is not a about reaching a number, is about not having maps that basically represent whole countries which are amongst the most geographically diverse on the planet. Only in what they call “andes” you can find up to 9 distinct biomes, i’m sure is the same for the other ones.
But this is a thread about european dlc, which I also encourage. I mean, compared to SA 8 maps, Europe 0 maps seems worst.
(I have a thread about how south america is nor well represented here: Maps and Minor Civs imbalance by region - Age of Empires III: DE / III - Discussion - Age of Empires Forum)