I don't feel Royal Authority should have extra aggro generation, since, ideally, I'd like for Paladin to be able to, at some point, become a viable off tank (I want the same for DRK) and stealing aggro constantly with your monstrous 350 potency aggro boosted combo doesn't seem very fun. PLD probably needs Halone to have its potency boosted to 290-300 and its aggro modifier increased so you use it less often and its less of a DPS loss. I'm not sure what I'd do with Power Slash, though, since while its a relatively small DPS loss on the combo its biggest issue is that using it slows down your MP regeneration, which is a long term DPS loss due to less Dark Arts.