The Man Keeping the Martial Down

[AMFV]

If you want a setting and system where the heroic "fighting man" of whatever sort can thwart dastardly spellcasters with wit and grit and steel and thews and agility, no magic of their own allowed (and again I am using "magic" here as broadly as possible, well beyond spells to fight spells)... then D&D is probably never going to be the system you want to use.

I agree completely! I would argue that D&D blurs the line between casters and martials at anything over medium levels. Which is perhaps why E6 was so popular.

Let me try something:

The amount of effort to create a character of a given power-level for any given archetype should be roughly the same.

I agree or at least the amount of effort to create a character of demonstrably lower power level should not far outstrip the effort to create a character of demonstrably higher power level.

Gritty fighters with realistic abilities.
World shaping magic users.
Balance between magic users and fighters.

Agree here. Although I think that it's possible to get ratios rather than they're binary options.

So you could have "gritty fighter with almost realistic abilities" and "near balance between magic users and fighters" and "Magic users with almost world shaping abilities.