I'm only on normal but I've been doing well with a 'run right at these fools' style party. I still use paladin heals, knockdowns, prebuffs with foods, and also potions. I still focus fire diligently. This style doesn't eliminate the need for micromanagement by any means but must simplify things quite a bit.
I too found this difficult at the beginning and I restarted a couple of times to tweak (min/max further) but the party never felt viable. I felt like I'd have to give in to 'tank and spank' tactics before I discovered two things:
1) The Opening Volly: You can vastly improve the performance of a six melee party by equipping guns or arbelests and murdering one mage (or priest) at the beginning of the fight. After that first volley switch immediately to melee weapons and bash away. This makes a BIG difference.
But the even bigger improvement...
2) The Paladin Skill 'Zealous Charge': I sometimes use the opening volly to lead in to the most difficult fights but only those. This skill changes everything. I play every fight in slow mode and my dudes still look like little crackmuffins chasing down nerd mages.
Give these a try - all I do in battle is to make sure that I go for mages types first, heal characters who are low, and focus fire when possible. I really think that these simple changes make a massive difference. My current party is doing fine without even six characters - I use my main character as a fighter, one other fighter, and two paladins - and I can travel with 'story' characters whenever I want.
GL