I think the issue right now is that Mantra + Dragon Kick utility is more balanced with DRG's burst, AoE, and multi-DoT situational utility rather than the considerable DPS increase for your BRDs, if you play with BRDs who can reach almost 300 ST DPS without it as I do. I think the goal of balancing the two would be making sure DRG + BRD sustained DPS is more in line with MNK + BRD sustained DPS in both stand-still and more phase-shift/RNG oriented fight, and then you bring whichever melee (or both) you value their utility for.
Some minor suggestions that could balance the DPS difference a bit more:
- Disembowel could be 5% piercing resist but buff DRG's damage (or just make Disembowel work at 10% for DRG only, 5% for BRDs) so they'll do more or less equal damage to what they do now, but the BRD buff will be less potent.
- GL3 in general could be more accessible (something like One Ilm Punch granting GL3 at the cost of a bit of immediate DPS loss), PB cooldown could be closer to 2 minutes, or GL stacks could fall off one at a time every 12 seconds. This would go a long way in balancing MNK to DRG in constant phase shift content, where not only will DRG + BRD beat MNK + BRD, DRG will just plain beat MNK.
- A minor, tiny buff to MNK's DPS, around 5 DPS or so in GL3.
Now, all that being said, I don't think there's a problem right now. For all I agree with Noctis and have experienced the same things playing with Allagan weapon DRGs and having an Allagan weapon on my alt with MNK, the difference isn't too large, and right now, as overgeared as we are for all content, it's more a min/max thing than anything. I'm going to play MNK as my main melee because I enjoy it more. The general public does not and probably won't really know that DRG is more optimal than MNK if one or the other, partially due to MNK pulling bigger numbers in BC on average, partially due to an appalling % of DRGs being the worst skill wise at least on my server (and unfortunately for melee classes, not being a skilled player will show that much more than if using a ranged class).
However, with THAT being said, in 2.2, if the primary blocker of progression is DPS checks as has been the pattern in FFXIV far more than healer/tank checks (who knows, Mantra/INT debuff could be key to a survival check in the future when lesser geared, but right now healers can easily handle all content in the game under-geared so I'm led to believe healing checks will not stop progression), you can bet the progression players will rather down content with less gear using DRG than wait a couple weeks for the DPS checks to be met.
Don't believe me that it's that big a deal? Have a "friend" parse BRD's burst going all out (for such a supposedly low end DPS class their burst is top notch), and multiply that by 1.1. Also parse DRG's burst over 10s vs MNK's over 10s. Also have your friend parse DRG's AoE over 20s vs a MNK's AoE in 20s, even using its once every 3 minutes PB. And then parse MNK + BRD vs DRG + BRD on the same enemy over 5 minutes. In every case the DRG's advantage will be far from negligible, the difference between clearing a mechanic in time or wiping a GCD before phase shift or enrage, the difference between wiping on T9 at 2% or killing the boss due to easily tens of thousands damage added over a long fight.
If they nerfed MNK, DRG would simply put completely out-class MNK. They're close right now, with an edge to DRG from a min/max perspective, in an environment with highly skilled players.