Enmity doesn't matter.

If you are 1 point of Enmity above everyone else, it's the same as if you are 1,000,000 points of enmity above everyone else.

So long as you are ahead of everyone else, you don't need any more.

Thus, Rage of Halone shouldn't be spammed, since it deals the least damage of all the combo's available to PLD and it's only purpose is providing extra enmity.

As far as the damage of the combo's go:

Fast Blade (160) > Savage Blade (210) > Rage of Halone (270) = 640 potency.

Fast Blade (160) > Riot Blade (240) > Royal Authority (360) = 760 potency.

Fast Blade (160) > Riot Blade (240) > Goring Blade (670) = 1070 potency.

There is a stark difference in potency of using Rage of Halone vs Royal Authority and Goring Blade. Royal Authority is essentially giving an extra attack worth of damage over Halone.

This isn't to mention that after reaching level 64 you gain access to Holy Spirit that has potency of 380 but costs MP to cast, which Riot Blade generates for you. Meaning that a Royal Authority combo provides MP regen while a Rage of Halone combo does not. With MP regen being very significant after level 64 (Even more notably after level 68 when you get Requiescat as a CD to play around, where you want to be capped on MP when it becomes available so to spam Holy Spirits for the duration of its buff)

However, if you're struggling for getting and keeping aggro, then yes, use Rage of Halone combo to help generate the enmity you need. However, do keep in mind that you want to ideally use Rage of Halone as little as possible.