Yeah that's true. Trigger Happy is capable of getting something like an 8 Hit Chain at the moment I believe, which almost doubles your damage. Definitely worth chaining up your big hits. And Black Mage gets a power spike as soon as you get the elemental Garment Grids since those casually give you the -ga spells for crossing all gates. The Gunner-BM-pair works better once you have those ^^

Almost forgot to mention, you can multi-target magic in this game, just like old-school FF games. Just press the side directional buttons during target selection to target all enemies/allies.

Do you see the button titled "Party Members" in your menu? Yeah that's where you change your party members.