If you think about it, its logical that the witnesses don’t actually carry out any punishment that requires skill. It would be inhumane
We know specifically that there was a court appointed malkus giver of specific physical characteristics.
It seems unlikely that beheading would be carried out by a stam witness. It takes skill, accuracy and power to take someones head off with one swift stroke. What would you do if the witness was 80 years old?
The idea of the witnesses initiating the death penalty has some meaning to it. Therefore, they have to actually do the act. It happen with their hands would not be enough. I suspect it requires willing and active witnesses. Other than this point, I agree with you. You are saying very good.