Just had a look at the countries' starting armies/fleets.
Russia and England start with 11 and 14, for example, while Brazil, Austria and Japan only get 4. Mexico gets just 3.
We could hook it up so that someone plays both Mexico and Japan, while another guy plays Brazil and Austria.
They still wouldn't equal the strength of the a lot of the other players, and their countries would be quite far apart.
Hell, keeping their countries seperated prolly isn't neccessary because even with combined countries they'd still be practically the underdogs in there.
yours in the name of science.