I used the following equipment for the playable characters:

Vaan: Knives, Swords
Penelo: Knives, Staves
Balthier: Guns
Fran: Bows
Balthier: Axes, Swords
Ashe: Swords

I mainly kept the characters using the weapon types that they are commonly affiliated with. I feel like there is a lot of individuality in the varying weapon types and equipping characters with whatever I felt like felt as though I was making every character generic copies of one another.