Half of all degrees offered and accepted by state Universities are proffered by wily street-wise older teachers and are potato-stamp degrees.

I'm sure there are foreigners with FECs awarded on account of fake degree documentation. As to the fraction of FTs who use such fakes, I think it's very hard to put an accurate figure on that.

Mind you I come from a generation which used to say if you are good enough to fib your way into a job, you're good enough to hold it. They are more than adequate to teach in China.

I agree with that. But it's the visa regulations that do not take that into account at all. That's why many public Chinese employers in EFL won't consider Westerners without degrees. Probably most of the latter know that the level of English required by FTs to do at least an adequate job as an FT here is seldom correlated to whether they are degreed or not.

Re Western culture in this respect - a hard-working and respected local Edinburgh councillor leader of a group of councillors was subsequently found to have lied on her cv re her academic qualifications, and was quickly pressured to tender her resignation. Had she not done so, she'd have been fired. That's the British way - honesty above all else, zero tolerance in this respect.
But in my opinion just because it's the British way doesn't mean it's always the way to proceed. I'd have thought that clemency could sometimes be applied on account of the exceptionally good overall work performance of a person whose dishonesty in respect of the above has been discovered!