Yeah, I'd say a BLM is the most powerful due to their sheer destructive power + dealings with the void + near limitless resources via drawing energy from the land

Followed by a WHM; same as a BLM in destruction if they choose to go that route + healing and drawing aether from environment ... potentially people, too if the CNJ questline is to be believed

A regular dragoon seems to be formidable. Very agile, and fighting dragons on a regular basis certainly qualifies as being very strong.

Warriors were the go to mercenaries at the time for their sheer power, but eventually were feared due to it.

A machinist can be formidable depending on their inventions

Everything else seem to be somewhat equal to each other