Your datfile does not have subfolders. Your archive does have a separated subfolder and a separated file.
And here we face the problem: Your 7z file stored such information separately, i.e. you have 1 folder and 1 file.
So clrmamepro detects the folder and says it is unneeded and removes it (which may cost a bit depending on solidness/etc).
Then it also finds a wrong named file...this is renamed with the rn option which takes no/very less effort.
So clrmamepro finds 2 things which both get fixed, one is an unneeded folder and one is a wrong named file.
Keep in mind, 7z (and also zip) can store files in subfolders without creating an extra folder entry.
This extra folder entry is the problem in your case. If file would be stored with subfolder information on file level in the archive, you'd only have 1 clrmamepro operation, a wrong named file "bla/wrong name" -> "correctName"
My example was a datfile with subfolders.
Subfolders are only supported when they are specified on rom name level like <rom name="bla/this is what the rom should be named.txt"...>
When having such definitions, the rebuilder and scanner will automatically create 7z without separated folder structures stored, but of course you still have subfolders in the archives....
I've attached an example for subfolders without extra dir entries. If you play around with that file and dat, you shouldn't see any extra effort in removing data, just pure rn operations when you alter the dat.
So, to sum it up: The problem in your case is that there are actually 2 operations and they are intented to be there based on the structure in the 7z file. Your example 7z archive keeps subfolder information separated instead using subfolder information on filename level. For clrmamepro, there is an unneeded folder and a wrongly named file. Reading the zipfile will give you 2 entries. This is completely independent from the external packing tools or the defintion of the dat.
However, rebuilding the files resolves the problem once and for all since it will create subfolders on filename basis