STR/DEX/PIE/ATK Testing

[Spider-Dan]

You aren't looking at the big picture.

What PIE does: Land debuffs
What will ARC become: BRD

PIE makes perfect sense to boost its Light Shot damage because you will want to load on PIE anyways to land the BRD enfeebles (when they are added).

1) You don't know that BRD is even going to get debuffs. They aren't getting any in the most current ability lists.
2) Why are you presuming that BRD and ARC must share modifiers? There's no reason why BRD and ARC can't have different modifiers. The game already has a robust infrastructure for changing the various formulas for an ability depending on which class/job you are currently on.