I would have to respectfully disagree.

Not necessarily because what you said is false but because of how smaller steering wheels on cars feel compared to large steering wheels. I had an old '80s era full sized pickup. It had a large diameter factory steering wheel. I can't remember how big but lets say 22 inches. I then wanted a cool small diameter Grant GT steering wheel on it. It was only 16-18 inches in diameter. I put it on and it was fine however it dramatically altered how the steering felt. I now needed to use more torque to turn the wheel but when i did turn it, it felt much more twitchy.

Its all about leverage. The big diameter steering was much easier to turn say 90 degrees compared to the small steering wheel. You get much more torque applied to a large steering wheel just because of how long the lever is. But it won't move as fast. On that small steering wheel, it was much harder to turn that same 90 degrees but when I did turn it, it felt like i was turning it faster. It is why big huge 18 wheeler tractors and buses generally have huge diameter steering wheels, they are able to apply much more torque for x amount of inches of steering wheel travel.

Leverage. Longer levers are easier to push but they don't push as much. Same theory goes for brake levers. Long pull levers pull a much longer distance of cable compared to short pull v-brake levers which pull less cable however the long pull levers pull that long distance of cable at a high torque whereas the short pull levers pull that short amount of cable with less torque. The long pull levers are much easier to pull a lot of torque with whereas the short pull levers aren't nearly as easy to gain as much torque.

In a nutshell, i would imagine that a longer stem (I'm assuming we are referring to the part that angles away from the vertical steering stem axis to the handlebar mounting point, correct?) would allow for more torque and lazier feeling steering compared to the shorter stem which would feel much more twitchy feeling steering.

This is all a theory of mine and if its full of bullcrap, please explain why and I will gladly rescind what I said. I'm here to learn but i am just applying my logical thought process of physics towards bike stuff.