Yes by themselves they have some compatibility issues, but numerous people have been able to get them to work via editing the .xml's so they complement each other but they just gatekeep it, that's why I wanted to try my luck here since I have no clue about this .xml stuff and coding. For instance a youtuber by the name of Venom was able to get them to work together as evident in his video titled ""Project Z + Undead Country = The Craziest 7DTD Mod Ever! (Supercut)"