The majority of people (estimated... Not like I took a census or anything) tend to just roleplay as the class and not the job, while still playing as that job.
That's not to say you can't, just know that, according to lore, most of these jobs are extremely difficult to actually be, if not genuinely impossible. To use a really strained example, imagine meeting someone in real life who claimed to be an ancient Egyptian Pharaoh. Sure, they may be telling the truth, but are you likely to believe them? Probably not. That's what the average person would think responding to any non-padjal claiming to be a White Mage.
That's not to say you can't, just know that, according to lore, most of these jobs are extremely difficult to actually be, if not genuinely impossible. To use a really strained example, imagine meeting someone in real life who claimed to be an ancient Egyptian Pharaoh. Sure, they may be telling the truth, but are you likely to believe them? Probably not. That's what the average person would think responding to any non-padjal claiming to be a White Mage.