Mnk has more HP, which is pretty game breaking when some moves can and will 1 shot any other job.
Nin has 4-5 shadows, Migawari and its respective de-buffs.
Thf has it's evasion but is limited being able to only sub ninja when tanking.

Drop rates red blue and grellow processions aside its just what you need at the time for what you plan to fight. All 3 of these jobs make holding hate a non issue, Atma's take care of that.

So if you don't have Sentinel's Scherzo you might want to go with a monk, however if your ninja is intelligent enough to know how to manage Migawari he can not only lessen the blow of an attack, but totally evade dmg that would have otherwise killed him. If none of this is the case, the world revolves around drop rates, Thf far out does both ninja and mnk in that department while barely skimping out on kill speed, and who cares about a minute or two more kill time on something if what everyone is looking for actually drops.