Uh... the Australian Army has been operating tanks since WW1 so it's not like we don't know anything about armour ops (hell, we exchange armour instructors all the time). I suspect it is because the Marines operate their tanks like the Australian Army does.
Yeah, that's a possibility as well.
I think it's because the Marine version is more like the export version of the tank - less network centered.
Could be too that the Marines and the Aussies are more like each other - back up? Sorry, my reverse gear is busted. I'll just go forward through the obstacle and come back through it.
My humble 2 cents!!
From what Ive read,most of the frontline US army units have now switched to the M1A2,some of which are also being upgraded for urban warfare & better networking.So there's not a lot to gain from them for the Aussies.On the other hand,the US Marines still mainly operate the A1s,which will be upgraded to the A2 standard.