Any decent PLD should be able to hold aggro alternating the Rage of Halone and Divine Authority when MT.
Rage of Halone debuff is what, 15 seconds? You can still keep it up all the time doing that, and eventually the other combo to refresh the DoT.

if it combo'd off riot blade like goring blade, i could see the use. use goring to put up a dot, and the new ablity till dot needs refreshing
That would be even less aggro then what we have right now, since Savage Blade has +enminty and Riot Blade does not...