See, I could maybe understand, say, all enemies having an actual Defense stat that Disembowel then reduces. I could even understand Piercing damage, if damage types are to remain either taking greater advantage of Defense Penetration or taking a greater hit from Defense normally (i.e. Blunt automatically ignores x portion of Defense, Slashing a lesser portion, and Piercing none at all, but has higher base potency to compensate), such that Disembowel has a stronger impact on Piercing damage than on Slashing and Blunt.
But even then you'd run into an imbalance between Full Party and lesser-sized parties, as whatever pDPS remains after making Dragoon rDPS-equitable in an 8-man party would be too little for it to be equitable in, say, a 4-man party. While this may be irrelevant until such a time as difficult content is made for anything other than 8-man content, it's a fundamental issue with all means of indirect damage contribution in this game, as each scales infinitely. A better solution may be to provide a modifier which depletes over actual (e.g. bonus damage) use, greatly tightening scalability (though potentially adding some additional rotational variance).
But having a sole provider of a damage buff, even a "mere" 5% one, hasn't been acceptable since its provider was already required just to avoid duplicate jobs (i.e. pre-Ninja Warrior). Unless Bard or Machinist somehow lose rDPS by lack of some alternative utility (e.g. an additional caster to Mana Shift them, in place of that Piercing buff, if they were actually worthwhile targets for MS) to make up for their pDPS bonus, Dragoon should not be the sole provider of such a large advantage. More even than it binds Bard and Machinist to Dragoon, it bind Dragoon to them, to the point than any other melee (except perhaps, sadly, SAM) would be better taken if no ranged DPS is present.

Originally Posted by
Kitfox
[Removing Disembowel and compensating Dragoon potencies for its personal bonus damage and rDPS loss] would be the best and easiest approach. They should do this to every weapon type debuff. would be the best and easiest approach. They should do this to every weapon type debuff.
That, however, seems unnecessary. Slashing and Blunt debuffs both manage to make something decently fun out of those debuffs. The only problematic one is truly just Disembowel, both in that it feels unimpactful for the Dragoon itself and has too great of scalability outside himself.