Everyone plays differently than the next person.
I myself as a white mage stand in the circle, wearing all vit accessories, and take all of the beatings. Often my health starts dropping to dangerous levels within less than a second, but that's why we have 2 other healers on the team, and why I have attunement, and why I have tonnes more cooldowns to go with that. They stand back and heal the ish out of me while I stand in my green ground and/or kite the melee around in the circle when attunement is down. By the time all of my cooldowns are used, the enemies' healers or some dps should be dead, thus making it easier to survive. That is if my team is good, of course.
It's all up to how everyone plays together, whether I (and therefore we) survive or not.