Good propaganda does not need to lie; indeed, it may not lie. It has no reason to fear the truth. It is a mistake to believe that people cannot take the truth. They can. It is only a matter of presenting the truth to people in a way that they will be able to understand. A propaganda that lies proves that it has a bad cause. It cannot be successful in the long run.
> those symbols would be their downfall.
It was actually "their need for symbolism," not the symbols themselves.
Also your graphic is wrong about the "black sun"