I won't put any spoilers here. I'll just say that I've been mostly following the main story and I'm in Act II just now leaving an Engwithan Ruin after learning something.
This is my current party:
Eder - Tank. Guans Pledge Flail, Fine Large Shield, Full Plate. I have him at 100 Deflection and high saves. He does like...no damage at all but can tank an army by himself. Essential team member!
Hiravias - He's dual wielding a unique Mace called raven something and a fine spear. I have him in Fine Scale Mail. His deflection is the next highest in line, I use him mostly for spells and mixing it up in Melee if the need arises (it usually doesn't)
Kana Rua - I think he's the weakest link I have right now. I don't know...I have him chanting Sure Handed Ila basically all the time and using an Arquebus. If and when I need his summoning I throw out a Phantom or Wurms (I usually forget about him to be honest in fights)
Natalie (Player Character) - Named after my daughter She's a Cipher wielding Lead Spitter Blunderbus and a Unique Pistol I found somewhere (I'm actually not 100% sure where I got this Pistol, but I barely use it) she's by far the best character in my team. She has the most kills, the most damage, but if the enemy gets a hold of her she goes down very fast. Low defenses, low deflection, very squishy but don't mess with her! Great spells.
Durance - I like this guy but I'm not sure what to do with him when he's not buffing or healing. I have him using an Arquebus as well. Should I change this? He has pretty good resolve and Endurance really...Maybe I should start using him more as a Fighter/Priest?
Aloth - I like this guy. I think his spells are great, squishy but useful.
The problem I have is, I feel like all of my damage is coming from two sources, magic and guns. I'm worried I'm a bit one dimensional with my DPS. If I can't cast spells I'm shooting guns, because Hiravias and Eder aren't putting out a lot of melee damage at all. I'm wondering if I'm going to stumble upon some enemies that just shrug off my guns/magic and then I'm stuck trying to have Eder poke him with this meager flail attacks.
Is there a better weapon I can grab for Eder or something, maybe Hiravias?