dammit kumagera
Hard or Lunatic? I have everyone around the four stairs on Hard and pretty much swarm in at once. Every time I've done that, I've cleared all the enemies on that Player Phase in time to combat Oboro and her lackeys the following Player Phase. On my recent Lunatic run (using the Birthright characters), I had Hinata choke the point where the ballista is, then on the following Player Phase I had everyone retreat back down. This causes the enemies to go back to their starting positions.