Job's I'd like to see.

[dinnertime]

Leveled both already. A bard is hardly a ranger and a gambling corsair or pure non-support gunner isn't what machinist is. They don't scratch that itch

Bard is literally Ranger but more. It even has Barrage.
Meanwhile Gunner/Musketeer is Machinist. The job only has one support skill and it's Dismantle. The rest are role skills.
Melee and magic DPS also have support in their role skills so they're not alone.

It's just an aesthetic issue for you.