2 copies?
Seriously: Title D comes after C
You either sort by Title or You sort by Author
What is first prevails
BUT there can be BIAS (in Calibre, but the device may not allow)
If you click (sort) the Title column,
Then sort the Authors column, the Titles WITHIN an Author will be biased (sorted) by title
As to your oddball multiple authors titles.
Verify the Author_sort value is proper (the Quality check PI has a whole raft of tests to help stabilize your metadata.