I dunno about that. The fact that soldiers feel fear, and know when to fold, was part of what kept the casualties so low.
Wiping out a unit of zombies is a lot easier than wiping out a unit of humans, because it won't break or even tactically retreat when it finds itself doomed.
I thought that breaking and running was generally what allowed massive casualties. Wiping out zombies is easier in the sense that if ordered they won't decline battle, but as a result you're actually going to be in combat longer, which greatly increases the chance of death and the like.
You're kind of both right.
Most of the casualties of a battle would generally happen after one side had already routed, as their victorious enemies ran down whoever they could catch... But simple fear also meant that remarkably little of the battle was made up of what we would think of as actual
fighting.
Fundamentally, we don't want to kill each other. Even more fundamentally, we
really don't want to die. All those depictions of ancient battles as two armies charging towards each to meet with a great clash and smash of swinging weapons and screams? That's mostly fiction.
What actually tended to happen is closer to mob riots vs police actions, or posturing between large gangs.
This is basically how the Republican armies of Rome dealt with shield walls.
Historically, professional soldiers have tended to be only a small part of a countries army compared to a majority of some form of levy or militia, essentially civilians with basic equipment. These people were the product of a violent age, but they were still people much like you or me, mostly unwilling to really kill one another.
So, you'd have two big mobs of soldiers swaggering up to within spitting distance of each other with their swords and their armour and their spiky bitz. And then they
stop. They start shouting at each other, banging on shields, hurling insults, throwing bits of mud and broken gear and stones - which the other side then throws back. A well-flung rock can be surprisingly deadly, so that will cause some injuries and deaths, but it's mostly about making themselves look big and scary. Like puffer fish.
Every now and then a small group on one side will psyche themselves up sufficiently to actually go and
attack, so there'll be a sortie from somewhere along the line, a brief scuffle of shoving with shields and stabbing with spears, and that'll kill a few more among the screams and clatter that rattles everybody around... and then they fall back, and they all go back to yelling and banging on shields and chucking stuff.
This state of affairs will go on for
hours, until finally one side just says, I've had enough! I've been standing on my feet all day holding this heavy godsdamned shield, I'm cold, I'm wet, I'm hungry, I'm pretty sure I'm standing in the piss of the guy behind me, I think I've gone deaf from all this yelling... I'm going home.
If they're really resolved, it might take a mass charge to tip them over that last inch, and a lot of the yelling and banging is to psyche yourself up for that. But in the main, that's it. That's your grand battle. An awful lot of yelling and mucking about, and then one side just leaves.
This is why professionally trained soldiers have historically been so important, because actual
fighting on a mass scale is
incredibly deadly.
@Pale Wolf can cover this in more detail, but the short of it is that there's far, far too much going on from far too many angles to really defend yourself for any length of time. It's messy and uncertain, and that's a very dangerous state of affairs when there's so many weapons about. Injury and death happens quickly, usually in a matter of heartbeats. Most battles had very low casualty percentages - but the great proportion
of those casualties would be from the brief spates of what we would think of as proper combat.
So, professional troops with the training and mindset necessary to seek out the enemy and truly engage them, often had a
profound effect on the battle. Their confidence and comfort with the hack and slash of 'real' fighting doesn't just make them less likely to rout, it also makes them an order of magnitude more deadly than militia troops, which in turn makes them more shocking and frightening, compounding their effects.
So, an army of zombies, combatants who are fundamentally incompetent but have perfect morale, is likely to take heavy casualties due to its willingness to give battle even on unfavourable terms. But the flipside of that is that its willingness to
give battle, period, is going to inflict heavy casualties which an enemy without perfect morale will struggle to endure, even without the extra fear factor of fighting the walking dead.
This is also why I said that the Ex3 system is rather good at simulating ancient world warfare, because it's trivial to cast all that shouting and banging on shields and throwing stuff as withering attacks to demoralise the enemy and psyche up your troops (reducing your opponents Initiative and building your own) to prepare for an actual
attack that will cause appreciable damage - or, in other words, a decisive attack.
