RoH as MT isn't really a sin, yeah, and I'd even recommend using it during prog - but after you and your healers get more comfortable with the fight it becomes a lot less worthwhile vs the damage you'd gain by not using it. I will say that it is strong against physical tank busters and, especially during prog, you'll want to apply it for those but otherwise it's just mitigating auto attacks which really aren't doing much to begin with and it's doing nothing if the autos/tank busters are magical. I guess to put it in a less black and white way is: If you're MTing and you feel like you (+ your healers) need the STR debuff more than your damage contribution, then use it in place of an RA - just don't use it as OT at all pls. :^P