Yellow Hornets Fighting on the Nest

Gatekeepers of Japanese yellow hornet (Vespa simillima xanthoptera, family Vespidae) fighting fiercely with other inbound workers for some unknown reason. I don't know why they fought each other. Maybe they were trying to expel the invading worker from other colony. I wonder if the fight was possibly a coup d'etat against the founding queen. On the other hand, the fight looked like a dominance behaviour among colony members in paper wasps. Note that the subordinate one were completely submissive (no fi