Interesting, thought they were mostly the same (FJ80 vs FZJ80 carrier)On a FF, You must pull both rear axle shafts and then the entire carrier (hogshead) out the front in order to even get to the cross pins. Way more work than pulling two axle shafts and drive shaft.
However, on a SF, if you break an axle you're dead in the water anyway because the wheel hub is supported by the axle shaft.
On a SF, you can just carry some spare axle shafts though, to your point. A bit lighter than a diff maybe.
I guess on the FZJ if your pinion or ring gear spits out teeth, you basically gotta pull drive shaft and at least one axleshaft.
Not to distract too much, but I guess on the 14B you can pull the pinion out the front, but with that 3rd bearing on the nose of the pinion there's more strength and less deflection to where (broken gear teeth) is less common.