I beat my first boss yesterday! My team consisted of Occultist, Jester, Crusader, and Leper, all level 1 (and pretty much my B team). They took out the Necromancer and no one even came close to death rolls! Occultist mainly healed and pulled targets from the rear. Jester had stress heal duty and bleed attacks on the 2-3 ranks, occasionally moving up and down the party ranks; I didn't even have the party buff skill on this one. Crusader was all about the stuns and backup melee, with Leper just wrecking my foes for me.
I'm still pretty early into the game at just under 6 hours, but super excited about the progress I've made so far. I still have a lot of stuff to learn (better party comps, for example) and need to do more town upgrades. I can see end game being grindy, but am loving the combat so far.