Yours fails to report that China is more successful than its size warrants.
Those that China does not win can more or less be considered to land randomly on other countries as it is the sum of them that represent the non-China component.
So far there have been 32 golds awarded. China (20%) of the world would have to win 100% of the golds to "win" in your system.
Requiring 20% of the world to win 100% of the gold to score as top is bungled math.
If tens of thousands of gold medals were to be awarded then your system would start to approach something resembling the circumstance.