pre:

Brute Force
Starting at 3rd level, you’re able to strike with your weapons with especially brutal force. Whenever you hit with a weapon that you’re proficient with 
and deal damage, the weapon’s damage increases by an amount based on your level in this class, as shown on the Brute Bonus Damage table.

Brute Bonus Damage

Fighter Level

Damage Increase  (or maybe even double the dice)

3rd     1d4 (2d4)
10th   1d6  (2d6)
16th   1d8  (2d8)
20th   1d10  (2d10)

Improved Critical
Beginning when you choose this archetype at 3rd level, your weapon attacks score a critical hit on a roll of 19 or 20.

Brutish Durability
Beginning at 7th level, your toughness allows you to shrug off assaults that would devastate others.

Whenever you make a saving throw, roll 1d6 and add the die to your saving throw total. If applying this bonus to a death saving throw increases the 
total to 20 or higher, you gain the benefits of rolling a 20 on the d20.

Remarkable Athlete
Starting at 7th level, you can add half your proficiency bonus (round up) to any Strength, Dexterity, or Constitution check you make that doesn’t 
already use your proficiency bonus in addition to any proficiency bonus you normally add.

In addition, when you make a running long jump, the distance you can cover increases by a number of feet equal to your Strength modifier you 
are counted as always being under the effect of the Jump spell, tripling your jumping distance

This was bad so try and make it a bit better.

Additional Fighting Style
At 10th level, you can choose a second, and a third, option from the Fighting Style class feature.  Both archetypes get this, so going to make it 
nicer  Any numerical bonuses from these fighting styles, or the one you took at 1st level, are doubled.

Archery
You gain a +2 bonus to attack rolls you make with ranged weapons.  Would become +4, this might be a bit much.

Defense
While you are wearing armor, you gain a +1 bonus to AC.  This would become +2 to AC.

Dueling
When you are wielding a melee weapon in one hand and no other weapons, you gain a +2 bonus to damage rolls with that weapon.  This would 
become +4 damage.

Great Weapon Fighting
When you roll a 1 or 2 on a damage die for an attack you make with a melee weapon that you are wielding with two hands, you can reroll the die 
and must use the new roll, even if the new roll is a 1 or a 2. The weapon must have the two-handed or versatile property for you to gain this 
benefit.  Doubling these numbers may be a bit much, maybe if they roll a 1, 2 or 3 on the die?  Or maybe give it 4e Brutal where you keep 
rerolling until the die does not come up a 1 or 2.

Protection
When a creature you can see attacks a target other than you that is within 5 feet of you, you can use your reaction to impose disadvantage on the 
attack roll. You must be wielding a shield.  Not sure how to improve this.

Two-Weapon Fighting
When you engage in two-weapon fighting, you can add your ability modifier to the damage of the second attack.  Also not sure how to improve this

Superior Critical  
Starting at 15th level, your weapon attacks score a critical hit on a roll of 18–20.  

Devastating Critical
Starting at 15th level, when you score a critical hit with a weapon attack, you gain a bonus to that weapon’s damage roll equal to your level in this class.

Survivor
At 18th level, you attain the pinnacle of resilience in battle. At the start of each of your turns, you regain hit points equal to 5 + your Constitution modifier 
if you have no more than half of your hit points left. You don’t gain this benefit if you have 0 hit points.  So both archetypes normally get this, so could 
double up to be 10 + 2x Con mod, or just 10+ Con mod HP