So, now Monk/Dragoon have to compete with yet another class?

[Grizzlebeard]

Still doesn't make having them logical, they're the same thing.

In FFXI canon they're not the same thing, that's the issue. Agility is to Vitality what Dexterity is to Strength. The former two stats bolster Evasion/Defense whereas the latter two buff Ranged Damage/Melee Damage respectively.