The point is that they stack with any and everything and are off GCD, so it can be applied at once the moment it is needed.
Regardless, someone has to be the worst. Machinists have literally everything from buffs, debuffs, all CCs, and great burst, and mobility, so it makes sense for that to be them. Even then, they only go marginally worse/even with Bards. Even a full team of Bards, when played well, can meet any DPS check.
As for ACT, look on Reddit, its documented by the guy who does the ffxiv plugin for ACT that it isn't tracked properly.
Regardless, someone has to be the worst. Machinists have literally everything from buffs, debuffs, all CCs, and great burst, and mobility, so it makes sense for that to be them. Even then, they only go marginally worse/even with Bards. Even a full team of Bards, when played well, can meet any DPS check.
As for ACT, look on Reddit, its documented by the guy who does the ffxiv plugin for ACT that it isn't tracked properly.