When using latex_documents to properly use the official LaTeX separator \and of multiple authors (for \author command), if they are enough authors to let the output occupy multiple lines, only the last line of multi-line display will be correctly aligned to the right margin.

(not using \and leads to overflow see #6875, and one can also try \\ which will stack things one above the other, but each will be centered, whereas the whole thing is globally flushed to the right of the page, and the end result looks quite bad)

Example in conf.py:

master_doc = 'index'
author = 'John Hunter, Darren Dale, Eric Firing, Michael Droettboom and the matplotlib development team'
# other stuff....
# latex config
latex_documents = [
    (master_doc, 'foo.tex', 'Project',
     author.replace(', ', '\\and ').replace(' and ', '\\and and '),
     'manual'),
]

which means that LaTeX file will contain this command

\author{John Hunter\and Darren Dale\and Eric Firing\and Michael Droettboom\and and the matplotlib development team}

It does correspond to the officlal LaTeX recommandations (cf this snapshot from the official LaTeX book)

But one obtains the following ragged looks:

Only the last line is well justified (due to #6005; but this also caused it to not abutt at same position as other lines).

The root problem is that the whole LaTeX mechanism for using \author data was initially thought out (3 decades ago?) for centering on the page the author names (article and book LaTeX document classes do that). The code in sphinxmanual.cls uses flushright but it did not modify what \and does, and it took over "as is" the original article or book class code (which uses tabular in order to be able via \\ to stack each author name on top of its address or institution, in a centered way).

For example it appears impossible without contorsions to have each author name on its line, aligned at the right margin. One can not do tricks inside \author{..} also because the contents must be genuine enough to not offset hyperref dealings.

The fix at #6005 was only for the case where all authors fit on a single line. But if they are many authors, or their names are long, the LaTeX code will create a multi-line rendering and only the last one will have correct alignement with respect to the document title.

A possible fix is to redefine \and command with gory LaTeX. Original definition is \end {tabular}\hskip 1em \@plus .17fil\begin {tabular}[t]{c} and if redefined according to

\DeclareRobustCommand\and{\end{tabular}\nobreak\kern-\tabcolsep
    \allowbreak\hskip\dimexpr1em+\tabcolsep plus .17fil\begin{tabular}[t]{c}}

this would fix the issue.

It is very far from providing a well though out template like structure for title page, but Sphinx code is simply very close to original LaTeX code from the 1980's which was very far from being easily customizable.