Ame-no-waka-hiko and Nigi-haya-hi-no-mikoto

Furthermore, can we infer that Nigi-haya-hi-no-mikoto was one of delegates whom Takami-musu-hi-no-mikoto dispatched from the heaven in order to subjugate Ashi-hara-no-naka-tu-kuni? If he had been a delegate from the heaven, Ame-no-waka-hiko should have been a most probable suspect.