Personally, I think the Chinese Navy will end up larger somewhere between 50% and 100% (twice the size). Very roughly speaking.
Remember, if the Chinese Navy is the same size, the US can still hope to win.
If China-US relations are bad, then I think we would see the Chinese Navy growing to 2x the size, to make the point that the US will surely lose if it attempts to use the military against China.
It would also be a huge geopolitical signal to everyone in the world that an alliance with the US is a mistake.
That is not the same as China being the world's policeman.
