The current Australian test cricket teams top five can be thought of in the same context as Sage 50. Perfectly adequate in their own conditions but when things change they start to struggle.
The Australian’s look far from the side they were in both the last Ashes series and the recent series against India. This is largely due to the top order failing to lay the foundations that has seen them be successful in the past. Without a solid foundation it is unsurprising that they struggle.