Take what I say with a grain of salt as I haven't leveled NIN and only roughly know how it works based on vids and my friends who play the job at end game, but that just sounds like a standard rotation. It actually seems like a priority system, similar to DRG.
I actually think Mudras are pretty sweet since it's sort of like Wrath for WAR. It's a new mechanic for melee that people will have to learn and get down to muscle memory, which does give it a bit of a steep learning curve. Messing up a Huton will definitely severely gimp your DPS for the duration that your Mudras are down, and while MNK has it's own unique mechanic in GL3, losing it is fairly hard to do unless the boss jumps or your keyboard catches on fire. However, I do think this is similar to DRG missing a positional, especially Heavy Thrust. Missing either HT or Disembowel basically ruins your entire (long) rotation, and you can either continue it hoping that eventually it patches up or you have to start all over. If a boss stays perfectly still, I'd say Mudras require a bit more work as you do have to pay attention to when they come back up. If a boss is twisting and turning, I'd say things either even out or are in DRG's favor, as DRG is then required to know when the boss will turn to not attempt going for a HT and ending up hitting the rear or Disembowling the flank.Then you have your mudra which feels like a completely separate mechanic on it's own. Always keeping Huton up and able to do a Trick Attack and Raiton before having to reapply Huton, keeping heavy surveillance of your bar (2 Raitons if you have Kassatsu up).
I'd say NIN is definitely different than the other 2 melee. All have their own unique things to deal with, and I'd say they're all on relatively equal footing. MNK has it a bit easier than both as missing a positional just means a single loss in potency, but neither MNK nor DRG should really be missing their positionals.
Anyway, would just be cool if all the melee were roughly on par with eachother. Give DRG some Utility, buff MDef, slightly more potency on stuff just to bring it up a bit and everything's square.
... Enix.