Couple of points
If you want to cause the most destruction, it's better to use multiple smaller warheads to cover a larger area than one big warhead.
You can see the evolution in size from the W88 to the W76 warhead. It also reduces the risk from ABM defences and warhead failures.
Plus if you assume that a DF-41 ICBM has 10x W76-type nuclear warheads, then the number of DF-41 ICBMs required is far lower than the 350 silos currently under construction, for most scenarios.
Personally, I don't see China going above 1000 deliverable warheads against the continental USA. That is more than enough for MAD.
And there to be a total of 1500 warheads overall, which is just *equal* to what Russia or the USA has.
I also expect the USA to go ape when this happens, and then start a self-imposed arms race at its nuclear *inferiority* to a combined Russia+China arsenal.
But if China has an economy 2x larger than the USA in 10 years time and China is happy with the current size of its nuclear arsenal, who is going to go bankrupt first in an arms race?
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As I said previously, it's kind of sad this is happening
But it's the inevitable logic of cold war competition
And the more than the US talks about Taiwan, the faster China's military spending grows