Here's what I'd like to see from the cards in a way that could help redistribute that power:

First, it frustrates me that Arrow is ultimately just a weaker Balance. That doesn't make it feel impactful, it makes it feel like I'm settling on less power. Second, Ewer and Spire are not useful on every job, nor are their effects powerful enough to really want to use over their royal road effects. Third, Spear just doesn't work; its design is inherently convoluted, difficult to communicate, and even more difficult to gauge who it's best to give to on the fly. So here's the solution I propose...

Balance: 10% Damage boost that doubles to 20% when used on a character in the Melee DPS role. 30s

Arrow: 10% Attack Speed boost that doubles to 20% when used on a character in the Ranged DPS role. 30s

Spire: 10% Critical Hit boost that doubles to 20% when used on a character in the Caster DPS or Healer role. 30s

Bole: 20% Damage Reduction (unchanged). 30s

Spear: 20% Reduction to non-global cool downs. Abilities that are currently on cool down are sped up by 20% or made active if less than 20% of the time is left on the cool down. 30s

Ewer: MP and TP refresh. 30s (duration doubled).

The idea here is that you have your 3 offensive cards that you prioritize based on your team, and that ultimately nerfs the AoE effect because only some party members will receive the 10% boost while most will only get a 5% boost to that source of damage.

Bole already has its uses, and the changes to Spear allow it to be less of a "quick I need to figure out who hasn't used their cool downs yet" situation, and allows you to reap the benefits of it regardless. And merging the MP and TP refreshes means that this card is no longer useless on non-healer roles and the doubled duration means that the actual amount regained is actually worth using the card with in more circumstances. You can also expand Ewer to help provide a hefty amount of resources to the team when players are running low.