It all depends on how the transmission and transfer case work.
If the oil pump or oil slingers inside the rearmost gearbox keep spinning and lubricating the gears inside while going down the road (rear driveshaft spinning but front input not spinning), then you're probably OK.
Other designs disconnect almost all gears inside so you don't have much inside spinning.
For vehicles that need the front input spinning to insure gearbox lubrication, you generally need to add in a rear driveline disconnect so the gearbox doesn't turn at all.
So yes, read the manual!