Let's take a look at some history. Back in the day, when we had the 1 vs 1 vs 1 game format, it was noticed that a regular pattern of the game was to have two teams work together and gang up on the strongest team, take them out, and then leave the two weaker teams to fight for the finish. After two years of this, Woodie Flowers stood up at the kick off and announced "We know that you are unofficially working together to play the game, but without carefully thinking how to make the best of your partnerships. So we figured that if you were going to work together, then we would make it a requirement!" Thus, "alliances" were born and they have been a part of every game since then. In other words, they took a weakness of the game structure and made it into a strength.
So now let's consider the 2 vs 2 vs 2 possibility. Bill and others are probably correct when they posit that with such an alliance structure we would see a repeat of the earlier behavior. The weaker two alliances would probaly gang up on the stronger alliance, take them out, and reduce the game to a 2 vs 2 format through to the finish. But is there a way to make this weakness in the structure into a strength? Actually, it is simple - if you just broaden your imagination and consider what might happen if the alliance structures are not symetrical.
If we know that the two weaker alliances will gang up and create an unfair 4 (2 + 2) robots vs 2 robots situation, then there is one very easy way to restore balance. Imagine what it might be like if the match were
designed to have two (weaker) alliances of two robots each, and a third alliance of 3 stronger robots. A 2 vs 2 vs 3 structure could make things very interesting! The team scouts and strategists would have a field day with this one.
But, nah, that is way too complicated. FIRST would never do that to us...
-dave