Your right Australia is inundated with modern Toyos because they are reliable, durable and competant. LR's opened up this country but even so Australians started to switch to Toyo because of their availablity, cheaper price (initially), on road speed and comfort, not because they were superior off roaders or better designed, the Toyos simply suited the average Australians needs more than LR.
Toyos were always more of a compromise car, whereas the LR was very much built for one purpose - offroading. The failure of the Land rover company and LRAustralia to listen to and respond to Australian customers needs and Toyos relentless and clever marketing sealed their fate.
Nonetheless there is still many LR's around of all ages, from series 1's to Disco 3's, whereas the oldest toyotas commonly seen are from the late 80's, and they almost invariably have significant rust issues. Further the LR was always the mainstay of the Australian Army, and yes they did try Toyos, however they found them to be lacking in ability and durability. However the Australian Army is reducing their LR fleet due to the move away from soft skinned vehicles since the rise of IED's.
And lastly for those comparing Series to FJ 40s, there are far, far more Series than FJs owing to their massive problems with rust, especially around coastal areas. In terms of longeveity there is no comparison, the vast majority of FJs rusted away years ago. And the FJ was never, in its standard form, a superior offroader compared to any Series.