Heres some advice. I dont know if it will help or not. I'm not gonna put this guys name on blast, but I'll call him Joe for this. And I've noticed this with a lot of Joe's.
Joe hears "Blu is the best DD in the game" and runs out and mercs literally every part of blu. Almace, tiz. Even the job itself to 99. Plays the job to master and finds out hes not doing even close to some of the best BLUs in the game. Hes not seeing the same numbers. Then he sees one of our CORs doing high Leaden damage. So what does he do? Goes out mercs everything again and still cant come close to our main cors parses. THEN he hears about smn.
Actually level your job to 99. Learn it. Get good at it. Slowly gear it. Find what works. Read forums. If you aren't making use of your job abilities. Or know that one might cancel out another and somehow your dual wielding remas? You really need to learn your job. All the gear in the game wont make you good.