The following addendum was made to the FileAndDirectoryOwnership
Another exception for directory ownership in packages is when there is
no clear dependency hierarchy.
Foo-Animal-Emu puts files into /usr/share/Foo/Animal/Emu
Foo-Animal-Llama puts files into /usr/share/Foo/Animal/Llama
Neither package depends on the other one. Neither package depends on any
other package which owns the /usr/share/Foo/Animal/ directory. In this
case, each package must own the /usr/share/Foo/Animal/ directory.