Its not that hard to make a Fighter ''more'' than what they are in regular 5e:
1: Fighting Style, Second Wind
2: Action Surge,
As a bonus action, you analyze the aura of one creature you see. You learn its current hit point total and all its immunities, resistances, and vulnerabilities. Alternatively, you can learn a one-word summary of the emotional state of up to six creatures you can see, such as happy, confused, afraid, or violent. You can use this feature PB/long rest.
Battle Assist: The fighter is adept at giving well-timed assistance; the fighter can take the Help action as a bonus action.
5: Extra Attack
6: Fighting Style (2),
Coordinated Strike: The fighter is adept at fighting in concert with a companion. When the fighter uses its Helpful feature to aid an ally in attacking a creature, that target can be up to 30 feet away from the fighter, and the fighter can deal an extra 2d6 damage to it the next time the fighter hits it with an attack roll before the end of the current turn. The extra damage is the same type of damage dealt by the attack.
Tactician's Eyes: You have proficiency in your choice of History, Insight, Intimidate, Persuasion or Deception. When you make the a check using the chosen proficiency against a creature you've targeted with Asses Foes, you have advantage on the roll.
Your toughness allows you to shrug off assaults that would devastate others.
Whenever you make a saving throw, roll 1d4 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.
11: Extra Attack (2)
13: Inspiring Help:
When the Fighter takes the Help action, the creature who receives the help also gains a 1d6 bonus to the d20 roll. If that roll is an attack roll, the creature can forgo adding the bonus to it, and then if the attack hits, the creature can add the bonus to the attack's damage roll against one target.
At 20th level, the bonus increases to 2d6.
14: Victory Before Battle: When you roll initiative, you can use this ability to grant yourself and up to five creatures of your choice within 60 feet of you a +10 bonus to initiative and the creatures have advantage on their next attack on the first round of combat. You must complete a long rest before you can use this feature again.
17: Extra attack (3)
20: Battle Lord: The die rolled for Inspiring Help become 2d6 and the die from Indomitable becomes 1d6.