Not sure what job you are using to fight them, but for red mage you might want to charge up your mana using other enemies before attacking them. Fleche, your combo-stop midway-use manafication, start your combo over, and finish one off with Ver-Holy/Flare. Then kite the other one using your spells again while avoiding the meteors at all cost. You should also have your own chocobo out to support you in the overworld, especially if you've leveled it as a healer or tank.