In the Duplicate File Finder tool the only option available is to keep the duplicated files or to delete them. Why not add a feature that would give the option of renaming the files we want to rename.

i.e AAA.txt (size 20 kbs) and AAA.txt (size 38 kbs). Rename AAA.txt (20 kbs) to AAA-REN.txt or something like that !!!