Machinist has the lowest 3-step combo potency of all jobs, even before adjusting for personal buffs. at 960/3. Yes, it has less 3-step potency than tanks do. Samurai has the closest potency at 1000/3, but Fuga and Fugetsu mean that it has considerably more damage than said 1000 would immediately imply.
Automaton Queen's "12 second" duration is actually only 8 seconds because of how long it takes to spawn in. It loses out on 360-720 potency's worth of damage because of this.
At level 94, Auto Crossbow gets a potency increase, but Blazing Shot is still only 220 potency.

Bard and Dancer have had potency increases to their big burst skills, but Machinist hasn't. Instead, we get another charge on Drill, which only helps you if you're able to pool that for use in a buff window and in the opener, and doesn't otherwise.

Flamethrower doesn't give any Heat when in use, it used to in Stormblood and is barely worth using because it doesn't.
The Heated [x] Shot upgrade is confusing since other than Dragoon, it's the only job that has partially-boosted combos at any level. And all 3 "Heated" versions were added in Stormblood but at different levels, and Heated Clean Shot is accessed at level 64 instead of in HW content. Heated Slug Shot deals more damage than unheated Clean Shot does at level 60.
It's fine on Dragoon because its single-target combo is changed in every expansion's level range.