If the history of teams have taught me anything they are way more likely to revert to type during a RWC than produce some master game plan. It may happen and it might win a one off game ala Japan V SA but reality is this will be won by a team playing the skills what they've honed for the past 4 years.
For England it will be whether they can string together those dominant performances where they completely steamroller a team (think Ire in this years 6 nations).....BTW England are probably my leat favourites of the 5 teams with a real shot.
For Wales it will be the attritional stuff trying to reduce a game to a low scoring affair and bring the side to come out in top. Again can't see them managing in 3 knock out games in a row.
Which is why I have a NZ V Ire final I think they both have the better game for knock out rugby. They aren't trying to play a perfect performance or percentages.
How are Ireland any more likely to win 3 knock out games than Wales?