Alexander had sent word to his cavalry the moment the battle started to get in formation and attack the rear camp of the Adhanians, destroying their supply base and hopefully even capturing the king of Adhania.
But he had not expected the Adhanians to rout at the very sight of them, and so the battle had progressed so quickly that the cavalry that had hidden themselves deep in the forest to not let their horses alert the Adhanians, had yet to come out of the forest and arrange themselves in formation.
But this had a butterfly effect Alexander could have never predicted,
Because, the king's escort, burdened and slowed down by its eight hundred, slow, on-foot infantry had the good fortune of meeting the fourteen hundred cavalries that were getting ready to charge the Adhanians rear side.