Well if you see the other thread, Sir Viv Stadium where we play Aus is a flat wicket and less conducive to pace bowling that has little variation. Bangladesh cant afford to ditch a quality spinner like Razzak against Aus, and take an erratic Rajib giving deliveries that come onto the bat.
Aftab is by far our team's best fielder. Batting and bowling alone wont contain Australia and South Africa. You need lightning sharp reflexes and aggression on the field to create pressure too.