A lot of peeps seem to be having difficulty understanding the concept of the Job System so I will try to use a real world analogy to explain. Military Operations.

If you are fighting a battle in an outdoor environment you want soldiers that are cross-trained in many weapons, tactics and basic first-aid. This way you can adapt to changing battlefield environments, pick up a fallen soldiers weapon, apply first-aid, even run away and regroup to try another assault tactic. Open World battles are less about teamwork and more about attrition and adaptability.

Special Forces Missions are quite different. You have a small group of highly trained specialists who must act as a team, each one carrying out his role to perfection in order to achieve a clear objective, whether it be capturing/killing Bin Laden, rescuing hostages, sabotage or even intelligence gathering. Each team member has a specialty (with some cross-class training) ie., Heavy Weapons, Sniper, Engineer/Demolitions, Medic, Communications/IT(computers). Think of Team Fortress or even Halo as examples. Yes each soldier can do the others job in a pinch but for the team to operate in top form and effeciency, each member must use his specialties.

So just think of FFXIV Classes as the well rounded, cross trained soldier that can be sent into any situation and has a decent chance at success if he can adapt to changing environs and enemies. (Open-World Quests and Grinding)

Think of FFXIV Jobs as Navy Seals or Army Rangers (specialists) who are sent in to a specific location to do a specific mission and rely heavily on teamwork to achieve their objective. (Dungeons & Raids).

I realize the analogy kinda falls apart if we are to believe that a Navy Seal/Ranger is useless out in the field apart from his team but I suspect/guess that The Grand Companies are somehow going to magically "imbue us" with these extra abilities/jobs just for the duration of the Mission/Dungeon/Raid.

Some of my thoughts anyway...probably wrong...usually am...so move along...nothing to see here.

http://youtu.be/4EYlXay0njE