Historically any battles came with loot; all victorious armies looted weapons and armors of the enemy and the resources the defeated enemy left behind : tents, horses, carts, foods, etc. Looting battlefield and obtaining enemy weapons and armors for gold when back in a city would be a great feature.
As in many case looting villages is forbidden, automatic looting of the battlefield might give great incentive and retroaction if nobles would get small amount of loot from simply participating in battles especially if it includes special items held by soldiers that could become artifacts (of lesser power than artifacts found by adventurers).
As in many case looting villages is forbidden, automatic looting of the battlefield might give great incentive and retroaction if nobles would get small amount of loot from simply participating in battles especially if it includes special items held by soldiers that could become artifacts (of lesser power than artifacts found by adventurers).