[nikkev]

This reminds me of the argument from Chasing Stars by Groysberg. It is very difficult to separate an individual's performance from that of their environment. A lot of factors come together, including individual skill, to influence someone's performance. If you take that same individual and dump them into another environment it is very difficult (or impossible) to reproduce comparable levels of performance. Applying this to teams, there are a lot of factors necessary for them to generate a high level of performance that goes way beyond the individual talent/knowledge of each developer. That's why its necessary to hiring needs to be about more than just knowledge but personality and cultural fit as well. Then you need to look at all the support structures that you mentioned.