The transfer case needs to see the front and rear drive shafts moving at the same speed. On a dolly the front drive shaft will not spin and can damage the tcase. Now that's what I have heard, however companies came out with unlocking hubs for the wrangler and I never heard of anyone blowing up their tcase. I think the communication issues is that you need to have the front driveshaft spinning at the same speed as the rear so that you can shift into 4x4 high while moving at a moderate speed.
If you get the wrangler you will love not having to deal with a tow dolly so I would look at getting a tow bar. I have used the cheap version but the adjustable one are easier but way more money. Tow brackets are easy to install and I used diodes for the tail lights.