Aundair's army pioneered many of the advances in the arcane arts over the war, with the Arcane Congress working on an endless stream of classified projects for the Aundairian crown. While Karrnath certainly has the lead in necromancy and even manage to match Aundair in abjuration and evocation, Aundairian war wizards provide a much broarder and more diverse skill set. Conjuration, enchantment, and transmutation are three key schools of magic where Aundair simply has no peer. Fog of War enshrouded formations of Thranish archers, Gallant Charge enabled formations of Aundairian soldiers to charge through enemy fire, and Mass Darkvision allowed elite Aundairian forces to strike even during the darkest nights.
More formally, Aundair's ordinary armies were supplemented by the Knights Arcane, a large order that included almost every noble who served in the war. The Knights Arcane embodied the mixing of arcane and martial traditions. Many of the Knights Arcane conventionally raised their own mounts to serve as traditional cavalry, mixing spell and blade from horseback. The Knights Phantom were an elite unit of light cavalry that preferred to leverage the spell Phantom Steed over flesh and blood mounts, using a special dragonshard focus item that extended the duration of the steed beyond the conventional one hour.
Perhaps the most famous of the Knights Arcane were the dragonhawk riders, whose mastery of magic solidified Aundair's aerial superiority. While Brelish hippogriffs, Cyran griffons, Thranish wyverns, and Karrnathi undead monstrosities all challenged Aundair's dragonhawk riders throughout the war, more often than not the dragonhawks came out on top. Still, this wasn't enough to prevent the major losses Aundair faced throughout the war. While a Lyrandar airship can be constructed in a matter of month, it takes years for a Dragonhawk to grow to a rideable size and war-ready state. Furthermore, the reliance on the noble class for both mounts and riders limited the overall size and scope of aerial warfare, something that may change if the next war were to break out.
Source: Politics of Aundair