Gladiator/Paladin Buff !

[Pooky_Pasha]

Nope, sorry, it is laughable. The skill itself holds no additional enmity generation, even with Shield Oath up, it generates about as much as one or two regular attacks from a Dragoon. If you have a Black Mage with you, it's entirely pointless.

FoF > CoS > wait 25 > CoS (+15s DoT) = 1040 free enmity potency over it's duration (40s) to all enemies in the area under Shield Oath. Even for single target, that amount of free enmity potency is hardly laughable simply because it's free.
CoS > wait 25 > CoS (+15s DoT) = 800 free enmity potency over it's duration (40s) to all enemies in the area under Shield Oath. Again, that amount of free enmity potency is hardly laughable, even for single target, simply because it's free.
FoF > CoS > wait 25 > CoS > wait 25 > CoS > wait 25 > CoS (+15s DoT) = 1840 free enmity potency over its duration (90s) under Shield Oath. Wait 10s for CoS to come off cooldown, repeat that sequence. That doesn't include the free enmity from Spirits Within.

tl:dr-Free enmity is never laughable.

Well, not really. It's a 30 potency each tick, so for every tick of 30, a DPS can uses one of his WS for much more potency...
But I think PLD can hold hate well, nevertheless

You're forgetting about whatever additional attacks the PLD does within that tick, in addition to that DoT tick. Essentially, the total amount of enmity generated over 25 seconds (CoS cooldown, or about 10 gcds) is what should be calculated. Whatever the PLD does in those 25s should outweigh whatever a DPS does for single target or AoE.