I don't disagree about Walcott and maybe against the strongest teams who play a more open game, or in Europe, he is a better option. But his control, vision and creativity in tight situations are not good enough to win us games against teams playing to catch us on the break. People underestimate how important Pires/Ljungberg were to our success from a creative point of view, and how few goals we scored from traditional "wing" play.
I know what you mean about Pires/Lungberg, but you forget that the team had a lot of pace back then. Cazorla and Giroud aren't as quick as Pires and Henry. To give us the right balance, we need Walcott's pace. We saw earlier in the season how important this is to our team. I actually think it would help against the lower teams to have a variety of attacking players with different styles. That's what we had in the Henry years. It makes us less predictable, and more difficult to play against. When the lower teams know we'll be passing it around their 18 yard box, they can park the bus and wait for us to make a mistake. We need variety.
I think that Walcott's pace is wasted when we are butting up against the 2 banks of 4, and a team parking the bus. At that point, it is more a question of acceleration and control, where Rosicky and Cazorla's little bursts of speed are more useful. I don't think Pires and Ljungberg would have come anywhere near beating Walcott in a footrace, but their burst speed, when changing direction was good.