Eva Lawrence you misunderstood my posting. The clerks I was referring to were those who created the manifests on departure from Europe.
I am not suggesting people did not change their own surnames around the time they immigrated, but the names were not changed for them and the names were not changed on arrival. No time frames or place markers are required.
Search the JewishGen archives and you will see that this subject has been discussed many times and the myth busted.