Just a list of images for the chest armor icons and what the closest thing to the source appears to be.  Feel free to correct/update:

The tank gear appears to have elements of both Ramza’s (the checker pattern on front, the cape) and Agrias’s (the shoulderpads and armguards) armor.  It’s also entirely possible they just wanted Ramza’s armor to look more tanky.

The Samurai/Monk gear seems to be influenced by specifically the female version of the samurai job from Final Fantasy Tactics.

The healing set is pretty clearly based on the outfit of Orran.

And finally, the ranged dps set looks to be influenced by Mustadio’s outfit.

The Dragoon is a recolor of the tank set, the Ninja is a recolor of the Monk/Samurai set, and the caster is a recolor of the healer set.