England just don't have enough players who can hit the ball cleanly. There is still too much emphasis on nudging the ball around and "building a platform". You have to look to hit hard from ball one in T20 if you want to win. All the wickets favour the batsmen. There are few bowlers who can surprise in that format (although England still struggle with spinners). If the opposition have a player at the top of the innings who can score 80 or 90 at a strike rate of 200 to 250 (Gayle, McCullum, Finch), you've got to match them. Jos Buttler is the best England have (on his day) but he rarely gets more than 6 or 7 overs to bat. Your biggest hitter should be there from the off.