The reason I have that many ready to go answer is because I am fighting the American (Controlled by a friend of mine, a retired LTC) on a wargame between China and Taiwan for a think tank judged by a bench of academic and ex-military. And I am ironically controlling the Chinese force and now at day 34, my force isn't making any headway into Taiwan.
There are a lot of different factors affecting how this war is going to be fought, mostly people think of the distant and the size between China and Taiwan and they would think there are more than enough resource for China to take on, afterall, China is 100x size of Taiwan. However, it's because Taiwan is small, China cannot put as much force as they think they can (or rather, most people think they can) on it, think of it like a funnel, you have a big opening and a small end, if you pour a lot of water into the funnel, you will just spill it instead of getting the water flow quicker, the same apply to the logistic in war. You can have your million strong army, but the coastline of Taiwan will not change simply because you want to land a million man on it. That's funnelling.
It's like a old fighter pilot saying. It didn't matter if you are 1 against many, there can only be 1 aircraft at your six all the time.
@gambit would probably can explain this better than me.