In the end, it allcomes down to Experience. Firstly, a chaos player may beat an order player because they probably played order before as well so they know the weaknesses, having played order itself. Also, i believe that chaos play order more than order plays chaos, therefore likely winning. However, a chaos player who has played for e.g. 50 times vs an order player who has played 100 times, the order player has a better chance to win. So, if chaos players want to beat order, then they need to either play as order as well to know what order fears against chaos or play more. Same with Order. Sobasically, to beat a different race, experience plays a role.