For starters, when an opponent has most of his troops stacked in one region, keep away from it. Don't attack adjacent regions.

This way you'll leave them landlocked for at least one turn, and that can be enough to take the lead.

It's also a way for you to maintain a good number of troops.
When you see you'll lose your bonus next round, cash it before other take their turn. And deploy them somewhere else, if you have a target of some sort.

If it's unfair to other players, well let them be the judges. Ratings are here for ...

Spain #1? People are getting realistic at last.
Brazil's overrated as usual, Argentina's got a wacky coach.

But USA as winners? Get real.

A tournament where one must win on maps of each continent, plus one of the whole world as a final?