Personally, I think the proportions are perfect as they are. Europe has some deadly battles as do the Americas and East Asia. The Middle East isn't too shabby, either. And I'm finding it harder to expand in Europe than the other parts of the world because of the high density of factions, which is a good thing! It makes you want to actually take your ship and go somewhere else when it's possible. Huge wars break out in Europe with two major factions attacking each other and their allies jump in! The "smallness" of Europe adds to the fun.
In Mesoamerica, the Aztecs and Mayans duke it out in a bloody, all-out brawl. And when the Apaches and Incans join in, oooh, it's just about as deadly as Europe is! I've had battles that were about 50% larger than any of my European conflicts due to the large amount of Mesoamerican armies swarming about and destroying cities left and right.
In far East Asia, the huge border wars between the Chinese and Mongols, the Chinese and Khmer, and Ryukyu and Japan give that sense of impending doom. Seeing Mongol hordes at your doorstep or hearing the thundering feet of the Elephants of Khmer really make you cringe. The close proximity makes you feel that pressure of "Hey, my empire actually needs protection!" That's a feeling that Total War should put on you.
The closeness of your neighbors entices you to think about what you're going to do and if you should do it. Poland is a flat nation with few natural defenses, so an invasion is inevitable, especially from Germany or Hungary.
Again, the proportions are as they should be: close and tense. This is a mod to represent the world in all its glory. While I do see how the expanded landmasses would dissipate the aggression and give room for your nation to grow peacefully (I love Rhye's and Fall, btw), it just doesn't fit in this mod, in my honest opinion.