Is there really an ideal stagger for a particular track? I used to race asphalt cars on a 3/8ths mile track. We ran roughly 2" of stagger depending on the weather. Asphalt sprint cars come to visit and they would run 4" plus on the same track. The radius of the turns didn't magically change when a sprint car rolled out of the pits.
IMHO:
Radius does effect stagger and in general a tighter radius will get additional stagger then a less tight radius. But IMHO, that's where generalities end and function and application begin. How much stagger works for you is dependent on the ability of what your racing to use stagger. A quick example is a winged sprint car as more ability to better use stagger then a late model and the ability of each is about the mechanical ability to apply weight to each rear tire when needed.
The reason stagger can give additional rotational effort from the axle with it's staggered tires, is because of the difference in surface speed between the two rear tires, available grip and how weight is applied to each rear tire.
I'll try to net it out speaking about the LR tire only. Somewhere on the track you must slow down and it's usually going into a corner. If your slowing down and you can push or hold the LR tire into the track, with it's slower surface speed then the RR tire, it will act as a brake or a rudder allowing the larger RR tire with it's faster surface speed to roll around it.
When even your asphalt car gets off the gas going into the corner, it instantly can apply weight to the LR. Then as soon as you accelerate weight and grip begins to leave the LR. You get your function out of stagger even though you only use 2"s of stagger, because of aero down force on your car preloading the LR while on the straight and the additional help when you let off. That's what slightly helps you into the start of the corner, along with your front tires.
The sprint with it's 4 inches of stagger... I have to stop because you did not say if they are winged sprints or not. If no wing they function exactly as your car and it's only their bigger tires with more grip that allow them to use more stagger then you. If there winged, then the wing will help them load the LR better and also help maintain the loading while slowing down and they are winged over. If you don't see them wing over, then there pretty much doing only what you do. Depending on the HP of the sprint and available grip, they may even setup to ride on the RR it all just depends on need.
I'll stop, either this made some sense to you and fit your question or it did not and if it don't fit, it is all just IMHO and ain't necessairly right anyway. ...