RTF is a global modification that replaces all towns in the game.

.... as someone who doesn't work with skeletons, I can't give a precise answer.
That is, the dwarf and the bear are one skeleton file.
I checked the skeleton - a bone comes out of the dwarf and attaches to the bear's back, which is unusual, so you can say that it's one skeleton.

Usually, it's not done this way - the skeletons of horses, riders, and weapons are connected only to the Global bone.

But it's possible that there are some peculiarities in Heroes 7, the fact is that the dwarf and its skeleton are stored separately from the bear, and Hannick glued these models together as he saw fit.