A change of battle tactics

It wasn't like the conquests of the North had been easy..fighting in the mountains among the harsh mountains, fierce animals, intolerable climate, dangerous ravines killer rivers had been an intense and draining experience for the soldiers. The loots were next to nothing, food was hard to come by, and butchering your steeds was not an option as in plains because the only way you could reasonably carry your weapons and supplies in the risky terrain was on yaks and camels. On the flip side it meant the enemies had to face the same difficult circumstances, and after a loss it would be very difficult to recover. A few decisive battles is all it had taken for him to win the northern wars. They had been brutal on the pscyhe, but not particularly bloody or difficult.

The southern plains were difficult. Your enemies would be informed of your arrival days perhaps even weeks before you got to them. They'd be well-prepared with a welcome party, planting in traps and dangerous militia operations on the way. The way they harassed his troops -- sending a small scout party to kill a horse there, steal a line of supplies there, was what he found the most frustrating. Their horses were faster, they knew the shortest ways, and could hide among the trees. They would come from nowhere and disappear into nothingness and there was not a thing he could do to stop them. He decided to change the formation, protecting his supplies with the bulk of his troops, in the center, with a light advance party ahead and a fairly strong defense formation in the rear, to protect against surprise attacks. The enemy change tactics to match to that. Instead of light guerilla on his attack party, they began teasing his rear guard, pulling them away from the full formation, and with his center exposed, picked off his logistics in the middle. His rear guard, as brave and talented as they were, were not designed to chase the enemy...they were meant to take on a strong foe head-to-head and absolutely annihilate them. The fast riders that he did have were all at the front

And yet again, there was a change in the formation.