I think you are posing interesting questions. Asymmetry and random factors in competitive games is not necessarily a bad thing. We can usually mitigate the issues that these factors would introduce by increasing our sample size. Lets say we estimate based on skill rankings that team A has a 80% chance to win and team B has a 20% chance. If both teams play against each other for 5 matches, theoretically team A would win 4 of the 5 matches. However, in practice it might be the case that team B defies the odds and wins all 5 matches. If we can increase our sample size to a larger number such as 100, we can decrease the overall effect of the random factors, which would then favor team A (the better team). The chance of team B taking the win is still always there. But the idea is that there will never be a perfect game. The only way to get around imbalances in a competitive environment is to keep playing the game until enough matches have been played to clearly declare a winner. There is a good presentation given by Richard Garfield here which I would recommend. Also check out this video if you want something a bit more succinct.