NIN/MNK difficulty?

[Bourne_Endeavor]

Beside being pretty much hardware dependant there's actually way more than simply doing your rotation correctly and using everything on cooldown, you have to adapt and you can optimize your whole rotation (and ninki rotation) depending of each fight, you also have to map every trick attack correctly to get the most rDPS out of it, same goes for enmity management.

Uh, how does this differ from literally every other job in the game? I have to adjust my opener on Samurai for better optimization on V3S based on Spellblade Holy, for example. Dragoon moves its buffs around to properly align with the raid for "burst phases." Mapping out Trick Attack isn't any different than maintaining Greased Lighting or BotD throughout phase skips. In fact, both of those can be far more cumbersome on specific fights. You seem to be creating this illusion only Ninja has to optimize their rotation based on a fight. Ask a good Black Mage or Summoner the sheer amount of micromanagement that goes into their opener and Ninja's isn't even close.

To answer the OP's question. I would rank Monk ahead of Ninja nowadays in terms of overall difficulty. For the melee in general: Dragoon >= Monk > Ninja > Samurai would be my rankings.