Originally Posted by
wind
It works both ways. Above all else the job system was implemented for distinction rather then strategic play but because of the distinction of classes it allows you to plan more appropriately hence the strategic party play.
But lets say your strategy called for a THM to stay a THM because of his versatility since your team makeup was bad that day/night. If he lost his 'jack of all traits' feel and became more specialized in one aspect and by doing so lose a spell that would make the fight much smoother. Your strategic party play just got fucked by him being forced to play his job rather then be versatile.