Also didn't the Romans suffer from inflation when they diluted the silver content of their coins in 3rd century to fund the wars and bloated Roman government. Wasn't this the reason for the fall of the Roman Empire?
You don't understand relative size. The USA is still the driver of the global economy. The Yuan does not have enough size and liquidity to replace the dollar during the cycle. China will first significantly correct because their corporate debts are the highest in the world now, their economy is incredibly unbalanced and dependent on exports and fixed capital investment (no worse example in human history).
Also I don't believe the US drives the world economy, the US profits at the expense of the other world nations by importing their goods in exchange for their paper. Yes the US has caused many bubbles in foreign markets but the biggest bubble is in Washington and I'm not saying China or any other country will come out of this good but the US are going to suffer the most.