Fix paladin. Only Class in the entire game that cannot...

[Kabooa]

So what you're really looking at is effectively a turn based battle system, with two different types of turns where actions can happen.

This would be true if the only actions taken in Final Fantasy 14 were ability / action choices, but they are not. Movement, environment interaction, auto-attacks, and other often encounter-unique variables exist, all of which have nothing to do with the GCD timer.

FF14 isn't running a variation of the ATB or Turn Based systems. They are running what most MMOs use as the standard now, and that's a Real Time GCD based combat system.