Well, all martial arts are similar, in their way. The techniques that work have been found hundred times. Sure, the same technique will be performed differently by judist than by wing-chunist, but it is still the same technique, same mechanism.
For example Robert Waschka (czech martial artist, who also worked on KCD combat system) has the idea that pankration was the basis of chinese kung-fu. Because Alexander the Great brought pankration to India, and from India it spread to China.It is possible, because earliest Indian martial-arts codex was written approximatelly in the time of Alexander's departure from India. And Chinese themselves traditionally say that their martial arts came from India.