Try not to spam RoH as an OT. Use it only to refresh the STR down debuff if the MT isn't a PLD, and use RA the rest of the time.

As an MT, well, how frequently you use RoH will depend mostly on how fast the rest of your squad rises in the threat meter. Otherwise just spam RA and RoH to refresh the debuff.

Sword Oath use will depend on how easy or hard it is for you to keep a comfortable enmity lead.