The term "staging" has a very specific meaning which should be defined as moving the trigger part way to the release point and holding it there, waiting for the sights to line up to finish the trigger pull. Staging is something performed by the shooter and is not a manufacturing feature. It is thought that this method of shooting will result in greater accuracy and/or faster response times.
I suppose there are pistol coaches that teach this method of shooting, but they are absolutely wrong. Even if the shooter has complete knowledge of how and when his firearm will actually release a shot, the method is entirely unsafe and very poor pistol technique. If in fact the hammer falls at different points during successive DA trigger pulls, the revolver's DA trigger mechanism is crudely made and poorly adjusted. Unfortunately, this is the case for most off the shelf revolvers. It can be improved by a good gunsmith.
Another unpredictable reality of revolver manufacturing is that only the most expensive line-bored cylinders will come close to perfect registration on all chambers. That means the exact timing of cylinder lockup will be slightly different for each chamber on 99.9% of all production revolvers. However, that part of the revolver does not affect the feel of the trigger pull. The requirement is that the cylinder locks up (carries up) before the hammer falls. That is a test that should be performed during checkout, especially on a used revolver.
The smoothest DA pull is found on the Colt revolvers, but a bit of hunting and extra smithing will probably be needed if you find a used model in reasonable condition. Ruger and Smith share the same trigger design. The only difference will be the quality of the finish on the parts, and correct adjustment.
Carry_Up