Are all german names ending in -mann Jewish and not real German?
As I have told you before, many Jews are German or are descended from people with German nationality. Why do you insist on confusing a nationality with an ethnicity? If what you're asking is whether you can be certain that a person with that name is NOT Jewish, then say so. But since many Jews have German last names, I doubt that that is ever true. Many other Jewish people have names drawn from their Russian heritage, or Spanish. This has nothing to do with political correctness. It has to do with your lack of knowledge of history.
Are all german names ending in -mann yiddish? NO
Why are German Jews not 'real German'?