You say you can't do this manually by opening 2 instances of file explorer, one of the left and one on the right? You know how that works I assume?
The files you want to move you move them from the right instance into the left instance and into the correct folder. Then you delete the empty folder on the right that the files were moved from. This would involve a manual sorting of files.
It's easier than selecting the "Move" option on the file explorer ribbon that involves more steps because you are just dragging files. Use the "Sort by" options on the ribbon to find similar type files in your folders.
Thank you for your answer.
Yes. I even tried a double-pane (double instance-like) explorer software. But even with that possibility, it would need be done manually with every parent folder - hundreds. Kind of thought of a macro keypresses software kind of AutoKey... Even with that, it is too risky because once done - and possibly failed, as I tested with a copy of a fraction of the troubling files, when there was mixed content - there would be no "easy" undoing option (hundreds of ctrl+z?).
I still think that CMD is the answer (or PowerShell), but I cannot find, adapt or figgure anything that works. Closest one I got somewhere, it failed when in subfolder was mixed content (files and sub-subfolders) but worked flawlessly when there were only sub-subfolders.
Or any folder management software, but I was also unable to find any that did the job in any way.