It might help to think this through as available torque vs actual torque and how this flows through the system. Torque is available 50/50 at the tcase but it isn’t actually felt by the front or rear dive shafts and then axels unless traction exists at each tire. The differentials complicate this because if a dif is open and one wheel doesn’t have traction then the available torque goes to the spinning wheel instead of the one with traction. This is why we have lockers.

In the scenario where 100% of the torque goes to one wheel you would need the other three wheels to have zero traction and then have the differential locked at the axel. Now that we have mechanically locked the wheel with traction it must rotate and because it has traction the available torque goes to this tire only.

Think of the scenario above but replace the driveshafts and axels with helical springs. Which springs will feel twist under load and which ones spin freely without resistance? The driveshaft and the axel upstream of the tire with traction are the only springs that twist up and experience torque under load. The other springs spin freely but dont feel twist at all. This is 100% of the torque going to the tire with traction (Ignoring drivetrain losses and waste)

For semantics of torque we are all saying the same thing but I think it’s still important to note that:
torque = force * distance = moment = “rotational force”
Torque ≠ force
Ft * lbs ≠ lbs

Both are vectors but bodies can be under both force and moment and it’s important to distinguish the two during analysis.