If it doesn't have low range it's not a 4WD and not suitable for going onto 4WD tracks. Fine for going to the snow but if you want go on anything serious you're stuck very fast.
sure if you need low range and you don't have low range then you're toast. if you need ground clearance and you don't have ground clearance then you're toast.
but i say a triple lock (at least a double lock diff - center and rear) is even more important. (see video below. these fellas probably only has a center diff lock and open diffs at both axles)
that's why the subarus are called soft roaders. but does the subaru 4wd work? well ... maybe watch this
These sort of videos are so dumb. If any vehicle was running the wrong tyre pressures they'd likely get stuck.
You neglected to mention the Subaru was heavily modified with a low range transmission, 3 inch lift and LSD.