Given a fantasy setting with necromancers that can produce armies of undead, would such an army really be useful against a fully-equipped but smaller human force?
- Zombies in this fantasy setting are magic based and are therefore unaffected by head injuries like other zombies.
- Zombies in this fantasy setting are smart enough to hold weapons, but not smart enough to wield them with any sort of skill whatsoever.
- Zombies in this fantasy setting usually wear armor.
- Zombies in this fantasy setting are controlled by necromancers, but the zombies in this fantasy setting don't seem to be able to understand anything except for the most basic of commands. (Attack, don't attack, move right, go left, and so on)
- Zombie army is shown to only use infantry units, with no cavalry or archers.
Also assume for the sake of argument that the human army has let's say ten thousand men (half as much as a zombie army), made up of an equal number of:
- Knights in heavy armor on horseback,
- Lightly armored foot soldiers armed with shields and swords.
- Heavy Longbow men.
- And have a small wooden Fortress that they can retreat back to.
All the men are well-trained professionals with competent commanders who know the strategies used throughout the Middle Ages.
My question is: would a zombie army really be an unstoppable threat (as shown in Game of Thrones and other fantasy movies and TV shows) or would a well trained, well-equipped medieval army with competent commanders easily destroy the less intelligent and untrained undead even if they were outnumbered?
Or would their lack of intelligence, skill, and inferior strategy make them easy prey for any competent medieval army?
Also assume that both sides have the resources to provide for at least light armor for all of their soldiers and heavy armor for their knights.
To clarify zombie army has 20,000 zombies, while the human army has 10,000 men.