here are many existing references that suggest an origin for the surname Witzel. Certainly, it is important to take each one into account. What is first noticed is that there is often some conflict even within the same text. And it must be asked if all views can be correct.
In a sense, these views refer back to Indo-European linquistic roots. These roots have formed families of words based upon an earlier meaning. It is in the ancient meaning of these roots that the evolution of a word can be traced.
So to begin a study of the meaning of the name Witzel, it is important to understand what others have said and why they have said it. In four linguistic groups, I have begun to present what others have said, without drawing too many conclusions of my own. In this way, all of these views are available for consideration for your investigation. My additional research is in the section entitled Linguistic Considerations. And, of course, from this collection of resources, you are free to draw conclusions of your own.