The Quality Check plugin has some options for 'fixing up' Author Names ==>>
Index of plugins
The Manage Authors feature also has a couple of features that might help,
Recalculate all author sort values and
Copy all author sort values to author. Right click an Author name in Book Details or Tag Browser to get at Manage Authors.
Suggestion: you might want to backup your library before using these tools just in case they make it worse.
Tip: Settle on some 'rules' and make sure you apply them
immediately after books are added to a library. Some of us add new books to an Intake library and make all metadata adjustments there before moving the new book(s) to the Destination library.
BR