I actually agree with this, wolfing. After six weeks of play since the game was released worldwide, many players have discovered which units/strategies are better than others. This would be a problem for multiplayer, I know. The only thing is that in the example I gave each player would be able to pick his own units, so he wouldn't be disadvantaged compared to the other player.
I hear multiplayer WON'T be in the expansion anyway. I said I'd prefer a new single player campaign, and that's exactly what we're getting.