Like fitness. If you can run a marathon you will outperform me, who can barely run one kilometer, on almost any physical activity. Whether it be running, biking, playing football, tennis, boxing, etc. Perhaps in some sports I would have an edge by knowing technique or tactics, but in most your superior fitness would be decisive.
I also think using terms like strong and weak developer is less stigmatizing than good and bad developer. You can get physical strength by lifting weights and developer strength by hacking a lot. My strongest colleagues debugged any system with equal ease; Erlang, Bash, C, Javascript, CSS, you name it. My weakest struggled with all languages and systems. Just my observations from years of work...