As a classicist, I feel obliged to write this post. I apologize in advance for any forthcoming nerdgasms.
In The Great Panic chapter of World War Z, Maria Zhuganova tells the story of her time in the mountains of North Ossetia, Alania. The crux of her account is the retelling of the events leading up to her commander's order to decimate their unit. The decimation order comes after a series of large military disorder:
1. Petrenko's refusal to kill the zombified little girl.
2. Arkady's bringing the zombified old woman into the barracks, and subsequent infection.
3. The small uprising that occurs in the barracks after the Spetznaz execute Arkady.
The reason, I think, that this process was included as a whole in Brooks' story, is the idea of fear. We talk a lot about zombies being a metaphor for dread, and a slave revolt essentially inspired the same dread in the Roman Republic. The generals in Spetznaz knew that the oncoming zombie fight was going to be ferociously taxing on their soldiers. The only way that they knew how to quell this fear was to inspire an even greater fear, of themselves, into their forces. This type of fear 'preempting' is historically resonant with the anxieties over a slave revolt for the Roman Republic. The Republic is filled with slaves, and the upper class inflict severe punishments upon those that revolt, in order that any ideas of a rebellion will be quelled. Whole households of slaves could be put to death if one of their comrades murdered their owner. In 10 CE, this even became a law: Senatus consultum Silanianum.
When each army confronts what they think of as their worst fear, the resort to terrible means in order to hold together the remnants of order and obedience.
When each army confronts what they think of as their worst fear, the resort to terrible means in order to hold together the remnants of order and obedience.
The decimation is brutal, and is intended to be so. One out of every ten soldiers in Zhuganova's unit are executed by their fellow troops. The troops were organized into groups of ten, and then these ten voted on which of their number was to be executed.
This method of execution is meant to inspire fear into the soldiers, and for the fear of their commanders to overpower any fear that they may face in the field. Zhuganova relates that part of the horror of the decimation process was that she didn't know what it entailed:
"To 'decimate'... I used to think it meant just to wipe out, cause horrible damage, destroy... it actually means to kill by a percentage of ten, one out of every ten must die... and that's exactly what they did to us."
Now to the good part:
This practice has a Roman antecedent!
And, the better part, although Brooks has changed around the workings of the decimation process, the essentials remain the same. (The Romans decimated by chance (lot), not by vote. Also, stones and clubs were used... but clubs would be for clubbing, and stones for throwing... not clubbing with a stone. But, details...)
Brooks' inclusion of Zhuganova's uncertainty over just what the decimation will entail, I believe, is a recalling of the uncertainty in the re-institution of the fabled procedure by Marcus Crassus, during the 3rd Servile War (71 BCE).
The story goes like this... The Roman Republic was having a very hard time putting down the Spartacan revolt. After two years of war going terribly, the senate sends Marcus Crassus to finish the job.
Crassus assumes the the title of Praetor, which is essentially high-command, when he arrives with his forces in the south of Italy. Mummius, one of Crassus' legates (officers), engages the rebels in an early fight... and he loses quite badly. Many of his troops wind up fleeing the field instead of fighting.
Crassus, in response to the early embarrassing blow, orders his legions decimated. This was not common practice. The other documented cases of a decimation order come down in history from Livy (400 years before Crassus' time), or from Polybius (300 years before Crassus). It is therefore certain that many in the Roman Legion would have been, like Zhuganova, very confused when the order came down to decimate their own ranks. I'm fairly sure this is where Brooks' inclusion of Zhuganova's confusion comes from, it's his own retelling of the confusion in the Roman ranks under Crassus.
The process worked, and Crassus' forces would lose no more major battles in the 3rd Servile War.
TL;DR: I think Zhuganova's response to the decimation order is an allusion to Crassus' decimation order in the 3rd Servile War.