Melee has the easiest holster out of all the other members. Since Rend Armor duty are assigned to 2 members, the rest of the Melee should be bringing actions that will be useful for the entire encounter.
Several things to bear in mind.
Do not use Lost Reraise. This Lost Action takes up a Duty Action slot. Instead use Both DPS actions: Lost Font of Power and Banner of Honored Sacrifice. Learn how to utilize them during burst phases. (FAQ here)
Banner of Honored Sacrifice is buffed with Pure Essence of the Duelist. If you use Essence of the Platebearer, the Banner has a bleed effect that potentially kill you. It is reduced with the Pure Essence.
Pre-Entry holster allows you to free up capacity for fights from Boss 3 - KP and beyond.
Melees assigned to Lost Rend Armor will bring along the following:
Banner of Honored Sacrifice
Lost Rend Armor
All other Melees will bring along:
Banner of Honored Sacrifice
Lost Font of Power
Being an MP Ranged is beneficial for mainly Healers on DPS Lost Actions, Casters using Font of Magic and Dark Knight using Edge of Shadow and Flood of Shadow. MP Refresh does not work on a BLM, unfortunately.
The advantage of this you can bring along Lost Shell II, more Resistance Reraiser since your holster is not filled to the brim.
For a Boss #3 holster, remove the Pure Essence and use an entry holster
Bring additional Lost Rend Armor to replenish the charges. Since Banner and Rend are not that heavy, Mimic isn't needed here.
Rend Melee has the most holster space and ideally should bring raid beneficial skills to be used at pre-pull. Since Rend Armor is easily obtained by appraising Forgotten Fragment of Contention, they can overwrite the charges with Protect / Shell at pre-pull for Bosses 3 and 4. Macro available
For a Boss #3 holster, remove the Pure Essence and use an entry holster.
May consider to bring Resistance Potion Kit for extra healing when needed.