Opens up Pandora's can of worms there.
I am unsure as to what current specialist historians think however from what I have heard anecdotally from some writers (e.g. Max Hastings), and what I would consider to be the case in terms of actual influence on the course of WW2 in all theatres, Australia's war effort on the battlefield was crucial in the period 1941-43, and less so outside those years. In fact it may be argued that our war effort had its most value strategically in terms of the economic and logistical support we provided nationally to the Yanks and to a lesser extent the Brits, through the provision of major bases (e.g. Freo's sub bases, the Empire Air Training Scheme run in dozens of regional RAAF airfields) and food and resource supplies.
Unfortunately, unlike in WWI where the AIF was in a position towards the end of that war to fight as a single large army unit in decisive battles against major enemy main forces (e.g. Villers Bretonneux, Hamel, Amiens), the Australian war effort during WW2 was spread thinly across multiple theatres, and was (through no fault of its own) often in sideshow battles or campaigns. Take as a case in point the invasion of Syria and Lebanon. The 7th Division was a major constituent part of the Allied effort in that campaign, however fighting the Vichy French in the Middle East was hardly the stuff of great strategic victories. Even our greatest achievements in land battles (Tobruk, El Alamein, Kokoda, Milne Bay, Gona/Buna) were limited in their scope and overall impact on the course of the war. The Nazi leadership and OKW viewed North Africa as a sideshow, and as for the Japanese invasion of New Guinea, that was more about negating Australia as a viable base for US offensives than actually conquering that island and then marching on us.
By the way, I write this not out of any disrespect to those who fought for us in WW2; I'm just trying to put our war effort in a more historically accurate context than what sometimes gets fed to us around ANZAC Day. Yes, the RAAF were very important for the night bombing campaign against Germany. Yes, our army, navy and air force were both effective and necessarily deployed in defeating the Japanese in their hold outs of Borneo, New Britain, Bouganville etc in 1944-45. However we never saw (unlike say the Canadians in Normandy or in the Battle of the Atlantic) the AIF/RAAF/RAN form a semi-autonomous national military force that had a vital and direct influence on a campaign in World War II that could've, if lost, led to an Axis strategic victory. For what were mostly political but also economic reasons Australia's crucial role in the Allied war effort between 1939-1945 was best wrought in individual battles or small campaigns which were at their peak in the period 1941-43.
Manfred, I take it you have come across some of the quotes from the Desert Fox about fighting the Australians ?
I'll stand corrected but if memory serves a couple Australian victories were labelled British or Commonwealth victories.
A bit like Andy Murray when he's winning