NHF – new heroes for Heroes V 3.1.

That's what I'm telling you, the main thing is that the file with the heroes is available, and where it is located doesn't matter (in mods, in data.pak, or in the map), as long as it has the correct extension.
The fact that it will be constantly changing is not a big deal; you can upload it with a fix, replacing the files on top of the old hero file.
...
The paths to the heroes shouldn't be like that + one error in a symbol (missed a comma or added an extra space) will not give a result.