I tried a PoE PotD walkthrough and some classes just dont work good enough:
1. Melee Barbarian. Takes a HELL of a beating. With Frenzy you cant control it good enough, so they end up pretty squishy.
2. Wizards. Blasts cant do anything, really. They hit for like 10-15 damage tops and mobs have so much hp its insane. Also limited casts per rest kill the class. Not to mention shades and shadows, who target mages 1st. You wll have to waste all your spells on defense and in the end ont do any real damage. Also almost all wizards AoE spells hit everyone, so you waste time to repositioning.
3. Melee rogues. They get instagibbed, literally. I had enemies do 120(!!!!) damage with a single strike on Eden, who had 97 deflection. Rogues just die.
A decent party, in my opinion, looks like that:
1. Pala tank for autoheals from kills. Moon godlike would be perfect, but i'm not sure about losing the head slot.
2. 2xChanters. One melee and one ranged for debuffs/buffs(2x reload and 1.2x ranged speed anyone?) and dps abilities/summons. Double summons are good too.
3. Melee Cipher. They are awesome and have plenty of Foe AoE's. No FF is a good thing.
4. Ranged rogue. Hearth orlan for crit bonus, arbalest for consistent dps. I had decent dps with War Bows also but i havent finished the game ye... so pick yer poison.
5. Ranged Priest for general buffing. Magran for arquebuse as main weapon and sword and shield if those pesky shadows will catch ya.
From available companions only Durance and Kana are any good. You can also take Pallegina, but her racial ability (+10 deflection against ranged attacks) is so-so and stat distribution is suboptimal.