Restoring the texture of Renegade Knights from Hammers of Fate.

I was digging around in the Editor's files, trying to replace textures using model files from the Heroes of Might and Magic III: The Shadow of Death Editor. The result was that instead of the flag being replaced with a shield, the flag simply adopted the texture of the shield itself.

You only replaced the creature's texture, but that's not enough. The geometry of the creature determines how the texture will be "stretched" onto it. To display the unit correctly, you need to replace not only the texture but also the geometry file from Heroes of Might and Magic III: The Shadow of Death.

and also... is it possible to do this in the form of a mod (.h5u) or as a file that needs to be copied to the data folder (.pak)? :3
Thank you in advance!

There's nothing complicated about it. Perform all the operations I mentioned and create a zip archive with the changes, preserving the path structure. For example, if the file that needs to be changed is located at data.pak\Characters\Creatures\..., then your archive should include the folders Characters\Creatures\...\ and the modified file. Then, change the file extension from zip to h5u.

P.S. Your attached images are not displaying.