Armies need scouts to know where the enemy is and sometimes to help make peace between two factions. These gods and goddesses are in the forefront of the warriors, opening the ways to war—or peace. Bast's face rides into battle on ancient Egyptian standards and shields, and it's said that she lays the hearts of Pharaoh's enemies at his feet. (Ew.)
Not only does Hermes serve as herald for the gods of Olympus, he's also a god of diplomacy. He's very good at scouting and can make peace or war between various factions. (Better hope he's on your side!)
For the Batak people on the island of Sumatra, Raja Indainda is a thunder god. He's also a great scout—some would say spy—who sees all and can direct the gods' messages.
While it doesn't seem like it'd be all that easy for a Norse god on an eight-legged horse to sneak around battles, Odin has two ravens who can make up for his lost eye and scout ahead of an army. Sometimes he even starts the wars by throwing down his spear or sending his valkyries out to change the tide of battle.