I think double caster team can be viable as well. Contagion have lot more utility if there is another caster in party. Black mage also benefit from mana shift as well. After flare summoner can mana shift blm and then blm can use one more flare than usually improve lot aoe dps. Mainly you wanna use melee + ranged + caster + 1 random dps. Last spot can be like any role.
