so, it's probably a late to the party addition but I believe that XCOM2 War of the Chosen is exactly what a mod toolset should be able to do. I'ts pretty much possible to do everything, next to nothing is hardcoded. The toolset itself is quite daunting, but the possibilities and the fact that xcom 2 mods keep being released to this day are quite great. it's not like Skyrim's toolset, quite easy to use but also quite limited when it came to hardcoded matters.