Ruri -
Hidden agenda is clouding your vision.
Broad, Anderson and Swann have been fantastic for some time now, often bowling sides out for 200-320 regardless of conditions. We don't need a fifth bowler, particularly when Bresnan and Finn are as good as they are. And Strauss seems to be better at managing four bowlers than five.
There are three weaknesses in this England team. One minor, one moderate, one major. I believe that together they create an argument for the six batsmen + Prior and four bowlers strategy.
The minor problem is the lack of a number six, but whether this solves itself or not, it shouldn't matter too much. We just have to keep picking somebody until it works. I still have hopes for Bairstow, who has scored his first-class runs this season in difficult conditions.
The moderate problem is the ineptitude against top quality pace bowling on helpful tracks. See Jamaica, Jo'burg, Perth. This makes South Africa favourites for the Headingley test. Although Swann probably gives us the edge at The Oval and Lord's is a toss-up, in no home test should England be the underdogs. For this reason, we should be packing the side with batting. Even then Dale, Morne and Vernon will provide our ten-long lineup with a serious challenge.
England's major problem is the inability to play quality spin, and the fear of everything that goes with it - mystery bowlers, men around the bat, scoreboard pressure. Tahir is obviously a long way behind Ajmal, and then Rehman, and probably even Herath. But there's always the chance a spinner can take a hatful against England, so weakening the batting is a no-go again.