They are explained in game as this:
1. Win a 3v3 multiplayer custom game with Very Hard AI allies using all three races against Very Hard AI opponents
2. Win a 3v3 multiplayer custom game with Very Hard allies against all three races of Very Hard AI opponents.
I thought, that this was supposed to go like this:
I make the 6player custom game, add 2 comps to my team and 3 to the oposing one. Get them all very hard AI, and when playing as zerg, my allies would be 1 terran and 1 protoss, and the opposing team would be the same, 1 terran, protoss and zerg. In one match. The achievement isn't counting games (zerg, terran, protoss), so it must be one game with all three races, not 3 protoss vs 3 protoss etc, otherwise It would be visible at the achievements page.
Right? What am I missing? What am I doing wrong here? I have a replay when beating a game like this.