Looking through every other jobs skill set, none of them seem to risk losing 190 Potency to a coin flip. Losing being the important part. Bard, Machinist and Black Mage delay a high potency skill it doesn't get lost permanently.
Monk risks up to 50 Potency, Ninja risks up to 60 Potency. And both of them have other options in this situation to minimize the Potency loss.
Such equality.
