Many "10x programmers" aren't anywhere near 10x faster/better/etc in an environment full of 1x programmers. I think "exponential" would be a better description than 10x. If you watch them in the short term they look similar to the 1x programmers. If you distribute their exponential gains over the whole team then this will always be true. These types are like successful hedge fund managers in the domain of technical investment and debt. If you let them work alone long enough you'll start to see their foresight paying dividends.