Cure V should be handed out to RDM and SCH. It still wont replace WHM, it will make them comfortable substitutes when the WHM is incapacitated = good support. Aren't RDM and SCH supposed to be supportive? Cure 4 spam is counter-supportive in a way. It yanks enmity between players and over time you will find the mob taking an interest to eating your face. What's that? Now you have to waste MP on the RDM or SCH to heal them.
If you WHMs still think that Cure V is your only hold on the top of the hill then learn to play WHM. And RDM and SCH who think they will be healing only or a "ghetto whm" you wont be, especially if they fix enfeebling magic vs NMs.