NIN = Fast, small hits (shorter GCD)
MNK = Fast, small hits (shorter GCD)
DRG = slow, big hits (normal GCD)
WAR = slow, big hits (normal GCD)
DRK = slow/normal, big hits (normal GCD, has lots of oGCDs to make it more active as well as a +attack speed CD in Blood Weapon)

PLD's a bit weird, but makes sense. Shield Oath = focuses more on blocking, therefore less hits with the sword though still autos more often than a WAR for example. Sword Oath = focuses more on attacking, more frequent hits with the sword. So you could say PLD is less GCD focused and more auto attack focused.