There has been some tweaks magicwise in FF4A, that may have gone unnoticed...
Some spells tend to either succeed if all targets succeed in being hit by the spell. These spells include Size, Toad, Piggy, and Stone/Break. This doesn't matter whether or not the targets are resistant to said spell (of course, if you are resistant, you won't be affected).
In FF4A, these spells don't behave in an "all or nothing" scenario. Any target succeeds in being hit by the spell gets hit by the spell (if resistant, then no change will occur).
Some enemy special/magical attacks like the Panther's Bluster only shows itself when the attack succeeds. The attack itself fails if you are resistant to either/both status attributes. However in FF4A, the attack still continues, even if you are resistant to both attacks. A wasted animation occurs....