As the game continues to progress without pausing and back addressing some ships as MajorJuggler points out, the game is becoming more list based and less skill based. I can walk into a nationals tournament with a Warmachine list that containers almost anything I want, and long as I have practiced with it I have complete confidence in a good showing.
Having played at Gen Con NA champs this year (while also having played since release at Gen Con a few years back), and playing against a VI Whisper + PtL Fel in every opposing list but one, I've fully decided that I didn't have a chance without winning the PS war against Whisper. Either you put your full 100 points at killing whisper and end up losing to the rest of the opposing list, or you kill the rest of your opponents list and end up running against a PS 9 Whisper with 1 or 2 ships that don't stand a chance.
At the current state of the game, I'd place list building at around 75% of your chance of victory - a vast majority of lists aren't going to cut it currently. After you clear the list hurdle, the rest is skill, but you just don't have tons of wiggle room when it comes to your list.