As a Chinese living in China, you must know the layout of the city does provide logical sense. I've only been once, and I buy stuff from factories fairly often. When I went there I basically went to a mall district where all the furniture was sold, then I went to the tile district to review tiles, I went to several other "districts" that where nothing but that single item.
I went to the window factory, which was directly beside more window factories, and directly beside that was the place that extruded aluminum for use. The aluminum they used was produced a up the road in what they called the metal district.
You are even saying that "industrial clusters in China" so there is clearly some amount of planning involved. There is obviously benefits to having all of the aluminum factories beside a aluminum producer, and having the shipping/packaging warehouses by the docks, etc.
There is some amount of government work at play here, either on a small scale or a larger scale to provide a reason for places to all setup.
I've also seen things that just are not possible in North America. Asked for samples of aluminum extrusions and had the die made and extrusion done in a day. Locally it would take months before a sample is at my door.
I've sent designs for quotes and get quotes in hours, half the time factory in NA doesn't even reply. And even when it does it's more of a "go away" then anything else.
I've seen live video of robotic factories building entire cabinets for housing.
There is some amount of rose coloured glasses in this thread. But we cannot deny that China wants business and can get stuff done fast and efficiently. That cannot be said for modern day factories in US or Canada. The work ethic and desire for business are just completely different.