The pictured black-figured lekythos features Hermes (in his role as a psychopomp), weighing the souls of Achilles and a Trojan warrior (Memnon or Hector):
What I find particularly interesting in the scene is the two winged male figures on the scales. According to the British Museum's description of the lekythos, they represent the souls of heroes:
Pottery: black-figured lekythos: the Weighing of Souls. Design black on drab ground, with purple accessories. On the shoulder, lotus-buds; on the body, above, an ivy-wreath. Contest of Achilles and Memnon (or Hector): On either side is a warrior, bearded and fully armed, thrusting with spear, each having a short chiton with purple spots; the one on the left has a Boeotian shield, the other has the device of a crab (?). In the centre Hermes Pyschopompos to right, bearded, with petasos, short chiton and chlamys, both with purple spots, and endromides, holds out a pair of scales in left hand, each scale containing a small winged male figure, representing the souls of the two heroes. In the field, imitation inscriptions.
From what I understand, Keres would be the more obvious choice to symbolize the souls of the warriors in such a scene. However, all sources I know describe them as female, not male.
What are these figures then? Do they have names, and do they appear elsewhere in Greek mythology?