Melee DPS shouldn't need Paeon (which reduces a BRD's overall DPS) at the start of the fight, especially if they have Invigorate (maybe 5-6 minutes in, sure). If in CT raid and one or more alliances have two or more BLM/SMN's (and a healer or two decide to DPS), then use Foe Requiem (which does NOT lower a BRD's overall DPS). It's a debuff on the mob, therefore it benefits all Casters (and DPS healers). If in a Light Party dungeon and your party consists of a BLM/NIN/SMN and DPS healer, then use Foe's.