I just make a separate folder and title it "not these" for the customers who send multiple files like this. Then I only keep the "final final final very seriously yes this is the final.pdf" file in the main folder.
DejaVu all over again.
We regularly get a file called 'final' from multiple customers.
They take on a life of their own as 'final_final' files in our local discussions.
Odds on ~>70% end up as final_final files.
You just can not make this stuff up.
A long time ago I had a customer looking over my shoulder. (They usually weren't allowed past the front office.) She literally had me move a word or logo a smidgen here, there, everywhere, and then back to where it started. She even asked me once what I thought. Oh, no, I'm not falling into that mine shaft.