I think it should be up to the individual how they play their class/job so long as they can do what needs to be done. If they could successfully tank as a GLD then so be it o.o

So many people seem utterly convinced that there's only one possibility for anything: if you're this class/job you must wear this exact gear with these exact melds and stand in this exact place to use these exact abilities at these exact times. I think it actually improves everyone's ability to play if they get out of that cookie cutter mentality. Throwing in something different but workable not only makes him as a tank think differently about what he's doing (and thus better understand his role and how to achieve what is needed), it might also give other players in the party ideas about their own roles that hadn't previously occurred to them because they'd never been in an unscripted situation before. It's being able to work without a script that marks the truly good players and the players who are first to take down new bosses and the like. They don't have a script to work from, they make it up as they go along, and they find what works by experimentation and flexible thinking. Fitting in the cookie cutter definitions only gets you so far.

PS. I'm not claiming to be a good player (I strongly dislike combat in general and tend to avoid it unless it's to see the story), just recognising traits that make others good and lamenting the player base's reluctance to do much of anything without following a guide. It was the good old days when you made mistakes and learnt from them.