how to find duplicate folders

hi,

i was wondering, how you can find out about duplicate folders?

example:

sda:  //pictures/2009/

with 100 pictures in it

sdb: //pictures/2009/

with 30 pictures in it, different from the pictures at sda drive

user share should look like

picutres/2009/ and containing 130 pictures

what i really like to do with unraid (even if its a feature, that you basically dont need to care) is to not distribute subfolder content over different discs

despite the capability to find out about duplicates (files only), is there a way to find out about duplicate folder names within user shares?

i know, you can set up unraid to automatically fill the same subfolders up to a specific folder depth

but since i bought new drives only when the others were full, some structures are a little bit "doubled". not "contentwise", but "folderwise".