[Sombre]

I think the biggest difference is diplomacy. From what I've seen of MP games, you /need/ to work out a peace treaty with some neighbours, before attacking the weaker one. In most cases it seems successful players sign a NAP (non aggression pact) with the first person they meet pretty much without hesitation. Being the third nation in a little group all in one area when the first two already have a NAP is basically asking to be killed and chopped up between the two of them. People like to win fights and most of the time that means double teaming you.