The problem with FFXII is that it offers options that just aren't viable. I once tried to play the entire game with battles set to Active Mode, but it just isn't viable in situations where you need to heal quickly.
That's because of the priority set upon queried actions, as since at least X-2, every action has an invisible secondary timer attached to it, excepting the basic Attack Command, and the developers know of this, and abuse the fucking shit out of it by designing bosses that put up some kind of basic attack pailing/immunity, overload the query/freezing all secondary timers, then proceeds to grab your player character by the hair and slowly punch your utterly helpless face in. The primary strategy for dealing with Zodiark in XII is to Mist Knack your way through the last 30% of its health bar or else you basically all but lose outright.
FFXII was a weird game where the Gambits can be really fucking powerful, but because the rest of the game is so heavily balanced against the player that they become almost completely necessary to do anything.