Regarding what to do so as not to do any harm

The book Dachshund Through the Snow was written by Rosenfelt - the audiobook was narrated by Grover Gardner. However there is an entry as if Grover Gardner was the author:
https://www.librarything.com/work/25810074.

I have added him as the narrator to the book by Rosenfelt should I just ignore the entry for Grover Gardner or should I combine it with the real book:
https://www.librarything.com/work/23043823

Thanks for any help.

These editions can be combined without causing any problems. I recommend that after you combine them, you go to the "Other author" field to confirm each contributor's role.

It's fairly common to find stray issues of a work with narrator as the main and only author. I agree with aspirit, combine and then confirm the narrator as secondary author - some editions. That way it will appear of the narrator's author page too. The only reason not to combine an audiobook with the original work is if it's an abridged edition.

I specialise in adding narrators and I have found a fair amount of narrators as being the author. Its also a good idea to recalculate the author/ title and perhaps wait a day to recombine