Just so I'm hearing you right, if you have a ZF 4x4 and need to tow it you can leave both drive shafts installed? Just put Tcase in neutral and somehow it pumps through both itself and the transmission?
I find that hard to believe but then again until a few years ago I didnt even know that you'll torch a ZF by towing it even in neutral because the oil pump is off the input shaft.
If you have the tcase in neutral, the transmission would not be spinning at all - wouldn't matter how the trans is. Just leave it in gear!
As long as the t-case has a pump on the output side to lube things(or gets enough lube from splashing), you'll be fine. Otherwise... well, at least it's just a t-case.
Alternatively, the 'long-distance' option that's been stated here several times is to just pull the four rear u-joint bolt/nuts and drop the rear half of the rear driveline. Now the only thing moving is the rear axle, which will be lubing itself no matter how it spins.