I'll have to watch later, but women fight scenes tend to employ more cunning, speed, and technique than just brute force. Legs are generally much stronger than arms for kicking, and wrestling type moves. So that makes sense. Hollywood fight scenes in general lack "realistic" strategy, but lots of martial arts use legs to entwine, grapple, and aid in locks like Brazilian Jujitsu, Judo, and Krav Maga (sp). If you watch MMA you will see some people employ these methods.
Of course MOST of the fancy flying around and twisting etc has little practical purpose, and I am sure some of the examples in the video are gratuidous. A lot of arts might have a drill that employs these types of moves, but they typically don't pan out well when someone is trying to actively defend against them.