Prioritize upgrading tower buff beams > and all auras by one or two levels if your monk tower health isn't great (to ensure tower buff beams don't get destroyed) > harpoons by crystal.
Place Monk auras as far from the tower buff beams as possible with them still being able to reach the tower buff beams.
Space the 2 harpoons and mortar far enough away from the slice n' dice so they aren't damaged by any splash damage the slice n' dice receives,
Angle southern most harpoons to be able to take out wyverns that spawn from the south and shoot enemies below. The harpoons above to deal with wyverns that spawn from the east and west.