I feel Machinist is mostly ok as it is, but loses to Bard in a few ways...

Warden's Paeon, BRD being able to remove or prevent statuses is extremely useful, would be nice if they gave something like that to MCH as well.

If they were to remake how the shots work, they should rework them entirely, as the current system of having a 50% to get to use the next shot with any actual damage (without using reload/quick reload) can have you just spamming Split Shot.
Maybe make it just a regular combo and rebalance the damages for that...

And BRD has 2 damage over time effects, the closest MCH has to DoTs is their turret, bring back Lead Shot.