Although no matter how much you prepare for something the dice can go against you, the more prepare you are the easier it will be when the dice go wrong. I am firmly of the belief that you can certainly outplay an opp and manage a win against a stronger list againt the odds with your tactics and knowledge of your list. The thing is at the gt, especially once you get a few wins in hand you will be playing against people who know there list well, and a tactically sound. Even with the strongest list it will be a difficult game, so if they are prepared for escalation and mission based games and your not then they have a big advantage over you.