Alternate 5E D&D Fighter

I have a long-standing dissatisfaction with the way that the Fighter has been handled in D&D. 5E has done slightly better in this regard, but the Fighter remains bland and boring, as well as underpowered. The most promising aspect of the 5E execution is the Combat Superiority mechanic, which was originally a core part of the class in the D&D Next playtesting but got shifted into the Battlemaster archetype. 

The following represents the best attempt of myself and the players from my All Things Under Heaven campaign to create a more tactically-interesting, evocative, and balanced interpretation of the Fighter.

(Credit for inspiration and some mechanic ideas goes to the discussion in this thread).

Hit Points
Hit Dice: 1d10 per fighter level
Hit Points at 1st Level: 10 + your Constitution modifier
Hit Points at Higher Levels: 1d10 (or 6) + your Constitution modifier per fighter level after 1st.

Proficiencies
Armour : All armor, shields
Weapons: Simple weapons, martial weapons
Tools: None
Saving Throws: Strength  and Dexterity OR Constitution
Skills: Choose two skills from Acrobatics, Animal Handling, Athletics, History, Insight, Intimidation, Perception, and Survival.

Equipment: You start with the following equipment, in addition to the equipment granted by your background:

• (a) chain mail or (b) leather, longbow, and 20 arrows
• (a) a martial weapon and a shield or (b) two martial weapons
• (a) a light crossbow and 20 bolts or (b) two handaxes
• (a) a dungeoneer’s pack or (b) an explorer’s pack

Fighting Style: You adopt a particular style of fighting as your specialty. Choose one of the following options. You can’t take a Fighting Style option more than once, even if you later get to choose again. You choose an additional Fighting Style at 13^th level.

• Archery – You gain a +2 bonus to attack rolls you make with ranged weapons.
• Defence – While you are wearing armour, you gain a +1 bonus to AC.
• Duelling – 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.
• 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.
• 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.
• Two-Weapon Fighting – When you engage in two-weapon fighting, you can add your ability modifier to the damage of the bonus attack.

Tireless: If you are under half-health and not unconscious, you regain hit points equal to half your proficiency bonus (rounded up) at the start of your turn.

Combat Superiority: Beginning at 2nd level, you learn manoeuvres that are fuelled by special dice called superiority dice.
Manoeuvres. You learn three manoeuvres of your choice, which are detailed under “Manoeuvres” below. Many manoeuvres enhance an attack in some way. You can use only one manoeuvre per attack. You learn two additional manoeuvres of your choice at 7th, 10th, and 15th level. Each time you learn new manoeuvres, you can also replace one manoeuvre you know with a different one.
Superiority Dice. You have four superiority dice, which are d8s. A superiority die is expended when you use it. You regain all of your expended superiority dice when you finish a short or long rest. You gain another superiority die at 7th level and one more at 15th level.
Saving Throws. Some of your manoeuvres require your target to make a saving throw to resist the manoeuvre’s effects. The saving throw DC is calculated as follows: Manoeuvre save DC = 8 + your proficiency bonus + your Strength or Dexterity modifier (your choice)

Martial Archetype: At 3rd level, you choose an archetype that you strive to emulate in your combat styles and techniques. Choose Champion or Mage Slayer, all detailed at the end o f the class description. The archetype you choose grants you features at 3rd level and again at 7th, 10th, 15th, and 18th level.

(Details of the archetypes to follow in a future post)

Ability Score Improvement: When you reach 4th level, and again at 8th, 12th, 16th, and 19th level, you can increase one ability score of your choice by 2, or you can increase two ability scores of your choice by 1. As normal, you can’t increase an ability score above 20 using this feature.

Extra Attack: Beginning at 5th level, you can attack twice, instead of once, whenever you take an attack action on your turn. The number of attacks increases to three at 19th level.

Indomitable: Beginning at 6th level, once per long rest you can choose to reroll a saving throw that you fail with advantage and using Strength. You can use this feature one additional time between long rests beginning at 11^th and 16^th levels.

Heightened Defenses: Beginning at 8th level, you gain proficiency in whichever saving throw (Dexterity or Constitution) you didn't choose at 1st level.

Improved Combat Superiority: Beginning at 9th level, your superiority dice turn into d10s. At 18th level, they turn into d12s.

Parry: Beginning at 9^th level, you can spend a reaction to add your proficiency bonus to your AC against one melee attack that would otherwise hit you. You can use this ability a number of times equal to 1 + Con mod per long rest.

Improved First Fighting Style: Beginning at 11^th level, you advance further in your mastery of your first Fighting Style and gain the further benefits listed below:

• Archery – When there are no creatures in melee range with you and a creature attempts to enter your space, you may spend your reaction to take a ranged attack against them.
• Defence – While you are wearing armour, your bonus to AC increases to +2.
• Duelling – When you are wielding a melee weapon in one hand and no other weapons and you roll a critical hit against an opponent, they are disarmed and their weapon flies 15ft away from them in a direction of your choice.
• Great-Weapon Fighting – Now, when you roll a 1, 2, or 3 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 take the higher of the two totals. The weapon must have the two-handed or versatile property for you to gain this benefit.
• Protection – When a creature you can see hits a target other than you that is within 5 feet of you, you can use your reaction to roll a number of d6 equal to your proficiency bonus and reduce the damage the target takes by the result. If this would reduce the incoming damage to 0, the target takes no damage.
• Two-Weapon Fighting – When you engage in two-weapon fighting and hit with your first attack, you gain advantage on the bonus attack.

Adrenaline Surge: Beginning at 14^th level, on your turn you can use a bonus action to regain hit points equal to 1d10 + your Constitution modifier + your fighter level. You may use this once per rest at no cost, but each use after this costs one level of Exhaustion.

Battlemaster: Beginning at 20th level, your expertise in combat becomes the stuff of legends.  You may double your proficiency bonus for any attack you make.  You may apply this feature after you roll, but not more than once per turn.