Isn't the issue more about design though? It seems to me that it'd be easy enough to take a random sample of chips made by your Chinese manufacturer, cut the to

Isn't the issue more about design though? It seems to me that it'd be easy enough to take a random sample of chips made by your Chinese manufacturer, cut the top off and verify it matches your design with a microscope. However if the complex product is designed by an adversary it's easier to hide a backdoor, probably also easier to plausibly claim it was an accidental bug.