D'oh, this was mostly a case of user error, i'd made a typo and read the debug messages wrong. *facepalm* Alive actually supports most of UNSUNG (only VC troops, i.e. "UNSUNG_EV" fail to load for me), so no compatibility patch is necessary. I will see if I can use ORBAT creator to mod in the UNSUNG_EV faction later today. I still advise anyone not to use the unsung faction mods mentioned at the alive wiki, they're badly out of date and will most likely break your game somehow.