I'd like to know what any of this has to do with the hypothetical situation I brought up. By the way, you didn't really answer your own question or mine for that matter.
As for the previous China Taiwan conflicts, I'd like to repeat myself, China did not have the capabilities and still doesn't have the capability to invade Taiwan. This takes time to develop, which they are.
Let make this clear here & now
The situation you are talking about is a hypothetical situation of a total invasion of PRC against Taiwan, right?
Let Assume wikipedia is right, PLA have a strength of 4 millions soldier, active + reserve, and ROC only have .4 mil
Problem with this and the Switzerland case I mention is, there are no "land" connection from China to Taiwan.
Now, when you have 4 millions soldiers, it does not always mean you are slugging out a match number by number...
Soldier does not appear in battlefield by magic, you need a mean to carry them from china to Taiwan in order for them to fight IN Taiwan. And you have to remember, no one in this world can achieve a 50% lift ability, not even the US, last time I check US is capable to lift 25% of its asset where they need to be anywhere in the world. In case you don't know, you are talking about 500k US soldiers.
If china were indeed invade Taiwan, they will only have a small fraction of those 4 millions troop at their disposal, on the other hand, Taiwan is the defender, they aren't going anywhere, so you basically need to eliminate the whole Taiwanese military, 400,000 strong to take over Taiwan. Let alone they have national service, mean there are not only 400k defender, but literally all Taiwanese male aged 18-40 are capable for defending Taiwan, that will bump the number to at least 2 millions defender.
Then you are talking about island warfare, where it seriously favourite the defender, unless china can gain total air dominance and naval dominance to a peer or near peer partner, it's literally a no way, no how
You need to look at a war scenario outside the number....