... . Body language is very important. ...
I agree.
I have used body language to turn black bear, not having to use the .44 mag in my hand.
I have also used body language to turn aggressive threatening dogs with only a rolled up beach towel, a kitchen knife or nothing in my hands being displayed as a weapon.
Body language is what turned those dobies mentioned in my OP.
This was the second time I've confronted aggressive threatening dogs while accompanied by a female with nothing in my hands to protect either of us with.
Sometimes body language fails.
If it does, I want to stop the threat without fail.
From the videos, I do not see the sjambok as being practically effective.
It requires too much effort to use it and it becomes ineffective when the threat gets too close.
The assegai on the other hand can be used to jab and slash so close that you might cut yourself in the process.
That is my definition of a defensive weapon.
Although, I would prefer to have a gun in my hand.