This may sound daft but does the position they bat at really make any difference?
I'm not a knowledge on cricket but surely batsmen should be comfortable at 1 or 6?
It makes an awful lot of difference when you've trained yourself to bat in a certain position, against certain conditions and then out of the blue you're dropped down the order in a totally different environment. The greatest example would be Ricky Ponting who has amassed an awful lot of runs and a decent average batting in the upper echelons of the order, however, when he batted at number six, he had nowhere near the same success. Michael Clarke is also very similar, he has proved himself to be a run machine batting at five with a good average yet when he bats at four, the runs and his average prove very susceptible. He averages 21.51 batting at four yet batting at number five he averages 63.41 - coincidentally, 20 out of his 23 test hundreds have came batting at five whereas he's yet to score a ton batting at four.
Naturally the great way to be a successful side is to have players of different techniques and abilities throughout the order. Each position in cricket allows for a trained skill - the roles are incredibly different. For example, you wouldn't want a side of Kevin Pieterson's because naturally for their brilliance, there will also be many failures. In addition, someone like Kevin Pieterson, a destructive batsman would find himself seriously in trouble against a new ball which is swinging both ways - opening batsman have a skill in seeing off the new ball which allows the lower order to amass runs. They need to set a platform batting with patience and skill and great concentration. Furthermore, you wouldn't want a side of Alastair Cook's either because the rate of you scoring runs would bore the nation stiff.
Australia have a squad which is currently very similar to each other. The middle order which in cricket are generally allowed to score quicker is now filled with opening batsmen who are usually patient against a new ball - instead, you are taking players away from their natural game.