I don't feel like DPSing in this game is complicated. The class quests describe what's important (PGL tells you to keep GL up and how to do that, THM talks about switching between UI and AF and how and why, etc.) and through playing it should be obvious what's effective. Some of the nuances may escape most players (for instance I'm never sure if I should open with DoTs on MNK or put GL up asap and then apply them fully buffed) but a great disparity shouldn't exist if people pay attention and use some sense. As such, I don't think they can do much to train the senseless to DPS effectively, though I rarely come across someone that's just outright bad at DPSing.