To clarify, I'm arguing that the metric is: (Net Earnings of Apple) / (Number of Apple Employees). What I'm saying is that the net earnings of Apple by definition subtracts out the money paid to Foxconn to build Apple's products.

I'm not arguing that the number includes the Foxconn employees in the denominator, and it shouldn't, because the numerator (Apple's net earnings) doesn't include money paid to Foxconn (as that's a cost of goods sold for Apple).

It is a better measure, but it's still pretty arbitrary. Apple could achieve an even higher profit per employee just by splitting the company in two: put all the capital in one company and all the employees in the other.

I wouldn't read too much into any of those measures.

They mean that what Apple pays to Foxconn reduces Apple's profit, but does not reduce Apple's revenue. Profit accounts for the cost of subcontracting.