[HoMM V]9 Race - Swamp! Is it needed?

I still don't quite understand how the creation of a new faction will progress. As I understand it, to add a new faction in Heroes 5, you need to work with the executable file. Moreover, you'll need to create models and textures for the units, as well as their capital city and outposts on the global map. This will require extensive testing and a significant amount of work. And that's assuming you can get the source code for Heroes (or at least disassemble it) and have the software for developing 3D models. And that's without even considering all the artistic and design work involved.