My honest opinion? Make all the cards the same and then change their effect based on the class that they land on. Make all the cards increase DPS by 3% in addition...
  • Melee DPS - Increase damage by an additional 3%.
  • Ranged DPS - Increase Crit/DH by 5%.
  • Caster DPS - Increase spell speed by 20%.
  • Tank - Counters enemies with 100 potency damage every time they suffer damage.
  • Healer - Reduce MP costs by 500.

The reality is that most people found Astro unapproachable because of the memorization and moment to moment decisions the class required in between very quick weave windows. By homogenizing the cards, the player can make choices, but is no longer required to actually remember what the effects are thus making it easier to onboard people into the class (and maybe even enjoy it). It will still allow optimization (should I increase the BLMs cast rate? Or will the increase to the SAM's burst be the optimal play?) while still giving flexibility depending on the actual numbers.

Either way- the current Astro needs a rework for their rework, because I don't see anyone actually enjoying it. (And, as a side note, them seem to be less desired compared to shield healers in the content I've played so far).