In fact, Australian/New Zealand forces comprised over half of the Empire's efforts against the Afrika Korps. It was Aussies that were behind the defeat and victory at Tobruk. Like the Scots, they took no shit and their air force beat the crap out of Rommel's tank superiority overnight. A-20 bombloads were too tiny to be of any strategic use, but a bomb bay full of 250lb bombs was perfect for ground support.
And the fifty caliber was more than sufficient for tearing up a Panzer 3 or Italian Semovente. The RAF caught on to the air support potential and soon 40mm armed Hurricanes and RAF Bostons were joining the effort.