Originally Posted by
Eidolon
Ultimately, all jobs are easy with small caveats that distinguish them.
Monk is positional heavy with an easy-to-maintain rotation that adapts well to all situations
Dragoon rotation, in the 2.x era, was complex but in return had not stacks to manage. With 3.x, they added stack management but simplified the rotation. So it's a bit more like Monk now.
Ninja's complexity comes from Mudra's. Their skills branch off from a single combo, making them the 'simplest' in this regard with the lowest positionals (Armor/Aeolian, and Sneak/Trick depending on situations)
Bard's all about oGCD management
Mechanist is all about Ammo management.
BlackMage is Enochain and minimalizing movement.
Summoner is managing stacks for Trance and DoT's, thus why they only have to maange 3 DoT's.