Yes, they are unique. I have tons of pins with the same prefix in both, pin name and number, and I want to copy them all and replace the prefix.
I can export pins, replace pin number in a spreadsheet editor and import pins again. But than I have to rearrange the pins agian. -> not a good solution
I have also considered to work with multiple slots and reuse the same symbol in the part (which would be the most elegant solution). But then the automatic pin mapping is not working and up to know I not found a way to import the pin mapping from a spreadsheed. -> not a good solution