My personal ranking puts HD Mod above VCMI (currently) but VCMI has some features that HD Mod will likely never enable - because they’re fundamentally game changing.
HD Mod also works with Horn of the Abyss https://heroes3wog.net/horn-of-the-abyss-download/ which is an (pretty successful) attempt to build an unofficial expansion to H3 that has the feel of H3. Anyone who played Wake of the Gods will know it felt quite “unH3” at points.
HD Mod also works (albeit in reduced form) with HoMM3: Succession Wars, which is a mod for Heroes III which make them look like Heroes II. It's WIP but it is charming.
https://sites.google.com/site/heroes3hd/
HD Mod also works with Horn of the Abyss https://heroes3wog.net/horn-of-the-abyss-download/ which is an (pretty successful) attempt to build an unofficial expansion to H3 that has the feel of H3. Anyone who played Wake of the Gods will know it felt quite “unH3” at points.