The scissors gaan sao is to be considered equally as defensive or offensive move. It protects the whole upper body from waist to head.
encyclopaedie
The jut sao is executed with the inner part of the wrist and serves as a preparation for further attacks like a punch or a fung hao.
Man sao is the searching hand. It serves as front line to take the first attacks of the opponent. The typical ving tsun guard position is man sao...