Chelmsford had underestimated the disciplined, well-led, well-motivated and confident Zulu. The failure to secure an effective defensive position, the poor intelligence on the location of the main Zulu army, Chelmsford's decision to split his force in half, and the Zulus' tactical exploitation of the terrain and the weaknesses in the British formation, all combined to prove catastrophic for the troops at Isandlwana. In contrast, the Zulus responded to the unexpected discovery of their camp with an immediate and spontaneous advance. Even though the indunas would lose control over the advance, the warriors' training allowed the Zulu troops to form their standard attack formation on the run, their battle line deployed in reverse of its intended order.  
The story that sandals were discarded to toughen the feet of Zulu warriors has been noted in various military accounts such as The Washing of the Spears, Like Lions They Fought, and Anatomy of the Zulu Army. Implementation was typically blunt. Those who objected to going without sandals were simply killed.  Shaka drilled his troops frequently, in forced marches that sometimes covered more than 50 miles (80 km) a day in a fast trot over hot, rocky terrain.   He also drilled the troops to carry out encirclement tactics.