> Over in Australia a few ranching families own so much land it makes the American figures look like rookie numbers

1/ Australia doesn't have "ranching" families anymore than it "throws shrimps on the barbie" - that's 'Merkin Engrish there.

2/ Gina Rinehart's massive station holdings come from her mining empire which was inherited from her father Lang Hancock - an iron ore mining magnate.

Sure, Lang sprang from Ashburton Downs, a sparse Pilbara lot of land:

   At the time (1918) it occupied 755,520 acres (3,057 km2) and was stocked with 19,000 sheep and 320 horses.

  In 1949 the property was carrying a flock of 30,000 sheep, but by 1951, following a severe drought, shearing had to be cancelled as the stock were too weak to be droved to the shearing shed.

  In 1979 the property was stocked with 300 cattle. In a good season the station is able to carry a herd of approximately 5,000 head of cattle.

~ https://en.wikipedia.org/wiki/Ashburton_Downs

but with brothers and an extended family there was no money there to made by Lang, he made his nut spreading mesothelioma * to the world and later convincing others to invest in vast mesa's of dense high grade iron ore, still being mined today.

FWiW the Hancock family drama surrounding the control of tens of billions per annum resources makes Dallas look a little rookie .. although Prix d'Amour** is bulldozed and gone now.

* https://en.wikipedia.org/wiki/Australian_Blue_Asbestos

** https://en.wikipedia.org/wiki/Rose_Porteous

Three farmers on monopolies and mismanagement in U.S. agriculture