What i think they should do is make the jobs like extension of the current class. This jobs should be able to equip or not at will, it would be cool if they are linked to the weapon you are using like with the armory system. Something like this:

Gladiator (Short Sword and Shield) ---------- Paladin (Long Sword and Shield)
.....................................................|----- Blue Mage (Dual Swords)

Marauder (Great Axe) ---------- Warrior (Great Sword)
...................................|----- Dark Knight (Scythe)

Pugilist (Cesti) ----------------- Monk (Knuckles)
..................................|------ Puppet Master (Claws)

Archer (Short Bow) ------------- Bard (Shot Bow and Instrument)
...................................|------ Hunter (Long Bow) or Musketeer (Pistols)

Lancer (Spear) ------------- Dragon (Lance)
.............................|------ ??? Don't know

Conjurer (Wand) ----------- White Mage (Cane)
.............................|------ Summoner (Another tipe of staff or maybe a book/grimoire)

Thaumaturge (Scepter) ------- Black Mage (Staff)
..................................|----- Red Mage (Rapier and Shield)


Each job will have access to all the skills the base class have and will focus the stats, new skills and the gameplay to something in particular. And they can add more classes and jobs like:

Rouge (Dagger and Shield) ---------- Thieft (Dual Dagger)
..........................................|----- Ninja (Dual Katanas)

Hear me devs!