Originally Posted by Sabardeyn
As I don't have a Kindle, I could be mistaken, so listen to any Kindle Gurus over my own poor advice.
If I understood you correctly, there are two issues here. One is inconsistent terminology while the other is the overlap between collections. For the inconsistent term, the following should correct the tags within calibre. You will need to change the tag used for all instances
of the wrong term.
- Open the Tag Browser and select the term to be changed/deleted.
Then right click on the tag and select rename, you can correct it to whatever you want. If that tag already exists, they are merged.