Ninja right now is both top DPS, and a huge utility class for the party. It probably should lean towards one or the other.
Dragoon really ought to be Second Place DPS, given that it adds relatively little utility to a fight. A better disembowel would help with that some, (15%, so that even without dot damage it buffs bards about 10%,) but even that wouldn't compare with Ninja's Goad, silence, group dot, etc.
I tend to agree that Monk should be top DPS, since they're relatively low utility outside that Heal Up move of theirs, Mantra, and since their rotation is more complex than Dragoon, even if it's currently a lot more forgiving.
After they soften the positional requirements, playing Dragoon well will become a whole lot easier than DRG. So, yeah, 2nd place highest DPS would be a good place for the class after that.
That said, I think all melee classes should be, "relatively," close to each other, in terms of damage output. That way even being third place isn't all that big a deal. That sort of thing really only becomes a problem when one class pulls far ahead of the rest, or another class falls way behind, (as was the case with Dragoon.)