Something else I find rather likely is that different people are working most effectively with different methodologies (a believe that is grounded in the repeat

Something else I find rather likely is that different people are working most effectively with different methodologies (a believe that is grounded in the repeated experience of being shocked at how other people program and still be effective). So it is entirely plausible there is a self-selection bias that people that work best with strong types don't work on projects with weak types and vice verse. I guess its really hard to control for that effect when you want to look at big projects, since people need to be willing to work on that for a long time.