If I understand the question correctly.. You want the players (Viewing the scene from a first person perspective) to only see the weapon and arms of the soldier while every other player who looks at a given player to see the full body of the soldier?

In that case I would probably use the "Culling Mask" property of the cameras and make a script that works something like this:

if(networkView.isMine){
    Disable_Culling_For_Third_Person();
}
else {
    Disable_Culling_For_First_Person();
}

This is not something I've actually tried doing before but it's certenly the method I would try out first.