I guess you don't understand what overcapacity means.
You started with a claim China doesn't have good cost-based options for Australia's natural and renewable resources, and it seems you realized that might have been a mistake, ergo you obfuscate by switching topic to steel-making. Okay, let's talk steel.
China has way more steel production capacity than the world can absorb (yes, the world), leading to efforts to reduce that capacity. Closing the loop by coming back to Australia; lower Chinese demand for ore has already resulted in mine closures, and under that circumstance, the buyer (China) has the advantage over the seller (Australia). Finally, China is Australia's biggest export customer by far, and Australian officials readily admit the country depends on China for its economic well being. Bottom line is there's a middle power depending on the largess of a great power, so the claim PRC relies more on Australia and not the other way around is wrong on facts and poorly reasoned.
Sure, we could get back to Japan military news, but try and remember you were the one that took my post on Japan military sales off topic.