I don't see any point in it. Swan is the treasurer and Costello is not. Costello was the treasurer.
To make a comparison at such an early stage of Swan's stewardship of the Treasury portfolio is just premature.
Costello did not single-handledly manage the economy during his time as the Treasurer. He of course had access to the full resources of the Treasury department to help him. The same of course is applying to Swan.
In reality, management of the economy is a collective government process, though the Treasurer does play a pivotal role in that process but he/she can be over-ruled by the cabinet.
