Blood from a Stone or: How I Learned to Stop Worrying and Love Historical Fiction

I like to read; I like to read fiction and non-fiction...  But what about historical fiction?  How much is real, "real" and just plain made up?  These are tricky questions but a good author will do his or her due diligence and, if you're lucky, tell you about it.

I was a the library a couple days ago and came across Ben Kane's Spartacus: Rebellion.  Ok, it's a novel but so what?  I am not averse to using the odd fiction in class (Saturnalia, See Delphi and Die, etc.) to educational effect but...  It's a case by case kind of thing.  In the case of this book, Kane kindly included a glossary and lengthy author's note. He includes details which are both helpful to suss out what he has embellished versus what is established fact, e.g.

It was my decision to describe the young Julius Caesar as one of Crassus' officers, bu the suggestion is not unreasonable.  He served as one of the twenty-four military tribunes in either 72 or 71 BC, and there is no mention of him going overseas, which means that he could well have been posted within Italy.  Given the slave rebellion that was raging at that time, it's likely in that case that he could have served in Crassus' army. (p. 432-433)

More to the point, his glossary is  simple and informative, even to someone who isn't reading the book.  Among the data I have yet to confirm or deny is that "The gladius was worn on the right, except by centurions and other senior officers who wore it on the left." (p. 443).  Some of his other facts check out, so...  One wonders where this information might have come from.

Quickly Robin, to the internet!  The Wikipedia entry says (basically) the same thing, buuut does give a citation: page 256 of A Dictionary of Classical Antiquities by Oskar Seyffert.  But hark!  Said codex hath been puteth unto thine interwebs by AncientLibrary.com.  According to Seyffert, the reason for this sinister behavior was that the officers did not have a shield to carry.  But while he often cites where specific information comes from in other entries, he does not give us any source for this...  And I begin to suspect the double-edged gladius of 'received wisdom.'  :\

At what point does the preponderance of logic and expert pontifications overrule the absence of hard sources?  Or do you just dig more?

Text citations:

• Kane, Ben. Spartacus: Rebellion. New York: St. Martin's Press, 2013.