First, let me apologize for upping the temperature. That doesn't help in the discussion, which I promise I am really interested in.
What I am having trouble wrapping my head around, I think, is what you specifically mean by "versatility." I think I came in with the wrong impression believing you meant "versatile just like the wizard in combat" and I don't think that's what you meant. So let's back up and start again.
Assuming we are talking about high level aka mythic fighters from legend and fiction, what are the core traits you associate with those figures that you want to emulate that simultaneously puts them on par with wizards ? Obviously strength of arms -- fighters should be the ones that fight the best. It's in the name. This should include, I take it, some limited use big guns (aka tear a giant's arm off). Next, they are almost always depicted as having superhuman strength and stamina -- not always superman levels, but certainly MCU Captain America levels. Maybe a feature where they get expertise in Athletics? Or they increase things life lifting capacity, jump distance, and movement speed? Finally you mentioned leader of men qualities. Do you mean having "summons" available in the form of soldiers, or warden like inspiration abilities or?
Yeah, same here.
Okay, so I'm always tinkering with a Heartbreaker or two (just something I do to scratch the itch when I'm not gaming or prepping for game). Maybe the ideas for the current Heartbreaker I'm working on would illustrate my intent. Obviously, since this is for a system I'm building, these ideas
cannot be ported to 5e 1:1. I'm simply trying to explain the intent.
Apologies, this will be somewhat long winded.
There are three classes in my system. The Warrior (Fighter), Battlemage (Gish), and Magus (Wizard).
Warriors get +10' speed, and Battlemage +5'. This improves with level.
A Warrior gets 3 attacks per round (Battlemage gets 2, Magus gets 1). Except for the Magus, these increase at higher levels.
Attacks can (obviously) be used to make attacks. There are also basic maneuvers like you would see in 5e that can substitute for an attack (grab, shove, etc).
An action that Warriors and Battlemage get is Power Attack. This allows them to make a single attack, but that deals a number of weapon dice equal to your number of attacks. So, for example, a Warrior power attacking with a longsword would deal 3d8+mods damage. A two handed weapon would add additional dice.
I suspect I know what you're thinking - that's mathematically disadvantageous. It's generally better to make 3 attacks at 1d8+5 each than one attack for 3d8+5. However, there are two things. Other characters will have features that can buff your next attack. For example, if your next attack automatically crits, 3d8+5 is better (since it's actually 6d8+5).
The other reason is because you can use power attack for opportunity attacks. Meaning that a warrior's OAs hit with the same force as that of a powerful monster.
In addition to the standard maneuvers, you also have Engage and Press.
Engage is basically the warrior giving special attention to a target. The target suffers disadvantage to attack creatures that aren't engaging it, and also the warrior can make OAs against the target as a free action (but only once per turn). Meaning that, an engaged target can't just let an ally trigger the OA and then walk away from the warrior consequence free.
Press allows the warrior to move their engaged target(s) up to half the warrior's speed. Think of this like when two or more swordsmen are dancing around a battlefield, their swords clashing in a dazzling display. You can't force an enemy into dangerous terrain (though you can drag them to the edge and then Shove them in), and an OA triggered by the Press movement only allows the one making the OA to Engage that target (it doesn't deal damage).
Between the 3 attacks they start with, the improvement to OAs, and the new maneuvers, I believe that a warrior would have strong battlefield control.
And obviously a warrior would get more than just this (this is just the core of melee combat). Probably an ability that improves base weapon ranges. Probably an ability to tear a monster's arm off. Yep, that is in fact on my TODO list. It would likely do a bunch of damage and render the arm unusable if they fail a save (half damage and disadvantage with the arm for short duration of they make the save). It would probably start off as an arm breaking ability at lower levels.
Utility. Everyone gets skills. A bunch at 1st level, and more as they level up. Most likely, every class gets the same amount.
The Battlemage and Magus both get battle magic for free, but other "schools" of magic cost skills.
The Magus must spend at least half their skills on magic. The Battlemage cannot spend more than half their skills on magic. And, to absolutely no one's surprise, the Warrior cannot spend skills on magic.
You can be proficient in a skill. Each skill also has specializations that you can spend skills on once you are proficient. Specializations are abilities that let you do certain specialized aspects of that skill very well. For example, Athletics might have a specialization called Wall Running which let's you do what it says. Intimidation might have a specialization named Terrifying Bellow that allows you to engage all adjacent enemies as an action. Arcana might have a specialization called Artificer that allows you to discern the function of any magical item. So on and so forth.
And, unsurprisingly, at high levels you'd have specializations that allow you to surpass human limits. Tear apart a porticulis as if it were made of paper. Steal someone's sadness. Know something by drawing it forth from the Akashic repository itself.
Magic has greater utility than specializations, but is based on a limited resource (unlike most specializations).
I'd like to reiterate that I'm aware that they couldn't do anything nearly as radical with 5e. It would require an entirely new edition, and might very well be too divergent for D&D. I recognize that.
However, there's no reason that, with the revision, they couldn't take some steps to at least move in a similar direction. For example, earlier in the thread someone proposed moving the Champion movement abilities into the fighter's core class, which I think would be a step in the fight direction. You'd need to replace it with something else in the subclass, but I imagine that professional designers could manage something. Give fighters another skill or two. Give them some decent core class features as they level, even if it's only something like a bonus to the distance you can shove a target. In no way do I think that I will get my ideal fighter, but that doesn't mean it couldn't be made significantly better.
