I think you just explained part of the reason why there aren't moogles in Selbina/Mhaura.
The Dunes and the Peninsula are the first places people really start grouping exclusively. They need to learn to depend on their party members and only their party members. This is why I hate power-leveling people through the Dunes: No one learns reliance on their group; they expect/hope for some high-level to come save their ***.
Already, when people die there they start going, "Is there a Raiser?" They'll lay there dead for 10-20 minutes waiting for a Raise - to save them a whopping 100 XP at most (4000 XP to level = 400 XP lost normally = 300 XP lost with Raise I), which could be gotten back in a single battle if they'd just respawn. If you could go to Selbina and change jobs, people would never release; they'd wait for a party member to run to Selbina, change to White Mage, run back, Raise them, run back to Selbina and change into their other job, then run back to the group again.
People already do this in Yuhtunga and Yhoator - and I don't object as much there because, at that point, White Mages should have Raise already anyway.