This is a unitrules mod that allows the Germans access to both the Tiger II and the Panzer IV tanks at the same time. There is no particular advantage to this other then for historical flavour as the Panzer IV will just cost you just as much for a worst version of the MBT that the Germans get as their UU for the same cost. However, you are free to mess around with the unit stats to give it more of an incentive to build one versus the other. To get the Mod, you will need to download the zip file, extract the xml file then make a copy of your original unitrules.xml file for backup, then rename this file and replace the unitrules.xml file in your RoN data directory. Thanks to Bunny-of-Death from Apolyton for figuring this one out.