What they should have done is use this exact system, except keep the old buffs for individual cards the same (excepting spire of course now with removal of TP). They should cut the potency of the old cards in half and then using minor Arcana should convert it into a new card with double potency. Arrow > Reduces weaponskill cast time and recast time, spell cast time and recast time, and auto-attack delay of a party member or self by 5%, or 'Lord of Arrows' > Reduces weaponskill cast time and recast time, spell cast time and recast time, and auto-attack delay of a party member or self by 10%.

Keep the new sigil system on top of the cards and keep the aoe effect as a 6% raid wide dps buff. This maintains unique-card-job-relationships.