An army of this size needs a strong network of sentries to ensure communication throughout the soldiers and can respond to incoming threats.
The wall outside of Madh-fushaum has enemies that never sleep, and are the eyes and ears of the army within. Any solid network of sentries has multiple layers, and the watch-towers along the wall make-up a strong inner layer.
The eyes and ears of Madh-fushaum, the Uruk-hai sentry in the watchtowers around the outer wall are entrusted with the safety of the entire army.
The eyes and ears of Madh-fushaum, the Uruk-hai sentry in the watch-towers around the outer wall are entrusted with the safety of the entire army.
The Uruk-hai sentries were battle-hardened warriors and a crucial aspect of the White Hand army. Removing them struck a blow to the safety and coordination of the forces within Madh-fushaum.