Machinist and Bard suffer from the distribution of utility issue where Bard got all of the utility but doesn't really lose enough dps to pay for it. Machinist pays utility for dps however much like rdm when compared to smn, it's doesn't do enough damage to warrant the utility it has when compared to other jobs.
Bard is Red Mage done right however, you could argue Red Mage is a more balanced Bard
Machinist is Summoner done wrong however, you could argue Summoner is just overtuned amongest it's role

This is really the problem with job balance and individuality, alot of people claim bard to be overpowered and needs a nerf but then when it ends up like rdm. it's under powered and needs a buff. Granted rdm has more issues as verraise isn't bad utility it's just niche. a more fair arguement is that Summoner is overpowered amongst the casters but if we nerf it, it'll just be in the same positionm that machinist is. If we buff machinist then Bard may end up like RDM. None of this even takes into consideration the fact that you could just stack them both in the same party. what happens when disembowel is removed but mch gets buffed to the point where double ranged is still viable. This issue is very complex