The focus part of many buffs are maxed out with lower ranks. No one is going to notice if you slip them an RK. II buff or even RK. I in these cases. The DPS uptick from RK. III spells is noticable for most classes in the parse. You would be silly to get RK. III buff over a DPS, or heal. We really do not need different ranks of most buffs - it just adds to confusion and waste time.