Getting for unit both Hero's Ring & Dual Wield while using one eq slot is great.
But. If you have both Zidane & Gilgamesh and you can acquire their TM's.
a) Gilgamesh TM is better if you have 4 better abilities than
- Snow: Champion's Belt / Gaffgarion: Bracer
b) Zidanes TM is better if you don't have 4 abilities that are better than CB & B
- Then you equip 2x CB or 2x B or one of both.
Genji Glove is my only way to get Dual Wield ability. And I do have 4 great abilities to fix the loss of 30 ATK (and other stuff depending accessory) from accessory. Actually ATK loss is not so high due to +10% ATK from Genji Glove.
Now one needs to ask, what are the chances to get these:
- Total of 2 CB / Bracer (or more actually) or equivalent accessories that are better than Hero's Ring
- Enough Dual Wield abilities to whole party (5 Zidanes)
Then one could ask does one need Genji Glove?
Then comes the part where you make different party for Arena & to everything else
So you need shitton of Genji Gloves / Dual Wields.
So the question of Dual Wield being better than Genji Glove is very situational.
You have made right choice to put Moogles to Genji Glove.