A section for same-game mods for the fifth one appeared on Nexus relatively recently.
https://www.nexusmods.com/heroesofmightandmagicv/
This is pretty cool because Nexus is a large and good mod hosting site with a huge audience.
I became interested in finding out their attitude toward ported content from other games in mods.
It turns out like this.
https://wiki.nexusmods.com/index.php/Porting_content
Interestingly, regarding Ubisoft games it is written:
"Authorisation for porting of assets is done on a case-by-case basis;
Contact the community manager for the game in question."
This information was not made up by Nexus admins, but taken from Ubisoft's own texts.
That is, in theory, Ubi really could grant such permission. And ideally, in the case of some games, it might even be beneficial for them. For example, assets from the relatively little-known Dynasty presented in the popular but old fifth one can be perceived as advertising a new project for old fans.
Now let's try to find this mysterious "community manager" and "contact" them regarding our "game in question".