my system I’m porting to UE4 is very close to the system you linked, it was actually a great inspiration when I made it with another game engine. my map is different and I use no pre-processed path calculations, only dynamic ones, but requires similar preliminary map decomposition. (somewhere I have a collection of references I used for creating my own system.)
I personally found the movement system and formation handling much harder to implement than the pathfinder (how often to update path to keep it dynamic and help collision avoidance, how to handle collision if it happens, how exact collision resolution needed, how to manage units getting isolated from their group, how to optimize its performance by minimizing bone-animation and ticking cost of the engine etc.).
so finally this topic is rather a C++ topic than of content creation 