While the militia of the Alliance army's right flank were locked in a tough battle with the orcs, Arthas on the left was also leading the forces of Lordaeron in an attack on the central Horde army.
Strictly speaking, this Lordaeron army could be considered the 'cream of the crop' among the three divisions of the Alliance army. The Kingdom of Lordaeron was powerful, and thus, unlike the lesser-equipped armies of other kingdoms, the army of the Kingdom of Lordaeron was almost the most comprehensive and integrated one.
There were Kingdom infantry for close combat, Royal Knights of Lordaeron for the cavalry, Dwarf mortar teams for ranged attacks, and even a large number of Mages and Priests to provide support in battle.
Compared to Altland, which consisted solely of warriors and relied on temporarily conscripted Adventurers for its magical forces, Lordaeron was in a league of its own.
