In actuality if you think about it Vader had an armor akin to the Samurai whereas Lukes movements were more like ninjitsu although with some Jujitsu handling techniques. I tihnk in general the martial arts are simply adapted according to who the actor is and what they are capable of but it is the element of the look and the weapon that is the key. MAybe age is why OB1 and Vader at an old age become like samurai, yet as youth they go more for the martial art warrior technique as can be seen in the difference of technique in OB1 younger to older...