It would reduce the number of PLD hands by between 50% and 66% (because many PLD weapon pairs are currently THREE(!) items) This would also free up some offhand armoury chest slots which could be reallocated to another equipment slot.
It would not, if implemented as OP suggests (and as I have outlined when I suggested this exact thing a couple years ago).
- Sword+shield equipped to main hand, no glamour => appears as matching sword and shield
- Sword+shield equipped to main hand, glamoured => appears as matching glamoured sword and shield
- Sword+shield equipped to main hand, offhand glamoured to a different sword+shield => Base (unglamoured) sword + glamoured shield
- Sword+shield equipped to main hand, both slots glamoured => sword and shield glamoured to mismatched equipment
As OP suggests, this also opens up possibilities for other jobs. RDM with a mismatched Medium. MNK with mismatched fists. NIN with mismatched daggers. VPR with mismatched swords. DNC with mismatched chakrams. Some of us like this kind of asymmetry.
Not the problem you think it is. Glamour info should be stored with gearsets, and the player's active gearset (that is, the system gearset that is what you are currently, now, wearing, not the gearset from the list of gearsets that you use to change the items in the system gearset quickly) should display whatever the last loaded gearset's glamour data was even when you equip new gear, as long as it doesn't trigger a job change (no more losing glams mid dungeon because you wanted to equip the new thing that dropped for you).
"But that's not how it works."
It can work however they decide to program it, and they really should program it so that gearsets store both actual gear and glamours.
"But you can't glamour an empty slot"
It can work however they decide to program it, and it won't matter that the gearset slot is empty if what gets displayed is the gearset's glamour data.
"But spaghetti code"
Honestly this stopped being an excuse a long time ago; let's not keep pretending they couldn't make this work if they wanted to.