Voadam
Legend
I would generally be in favor of the Buffy the Vampire Slayer RPG style approach.I don’t know how to adapt the game to solve the narrative utility of non caster classes.
In there the supernatural Slayer role is powerful and awesome at combat and durable, etc.
The Witch is powerful and flexible with magic.
Everybody else in the group are normal people who get a bunch of hero points or whatever they are called. They do normal people type stuff but the hero points give them some ability to mechanically pull through and/or narratively have things work out for them.
In D&D if the non magic classes had a pool of resources to narratively but non magically accomplish things I think it would be great. If rogues and fighters could get bonuses on saves or attack rolls or skills that magic types don't it would help balance them. If they got nonmagical narrative plot abilities of things working for them (perhaps rogues could flashback to the prep they did, or to define some useful appropriate environmental elements of a scene, or whatever) it could be a balancing power for them.
I really liked the 4e martial powers, but those were generally designed to be balanced against magical powers designed for the same combat power. For nonmagical utility powers I think plot and mechanical meta currencies could be a good way for D&D non 4e martials to keep up with the utility of D&D magic classes.