Auto-translated
It seems I've lost track of the conversation a bit. Let's go over it step by step and in more detail, because it's not clear what we're talking about in just a few words:
1. Rebalancing existing factions - which ones? It seems we've already decided about factions from different mods. Taking the "Holy Mission" approach to rebalance any set of creatures from NCF with color correction of textures in Photoshop, or using unfinished pre-alpha graphical assets, doesn't appeal to me (if anything, theoretically, you could balance squares with the inscription "I am a level 2 creature" and create factions, but in my opinion, Heroes 5 has a quality standard, and new factions should meet it). If we're talking about the original factions, I'm generally satisfied with the balance in the "Trials of Endurance" expansion, except that the Orcs and Necropolis factions are extremely powerful in the late game, but this is a feature of their mechanics, and the only thing that could help is removing the free converter to undead and nerfing "Blood Rage" (but we still need to figure out if it's possible to do this without access to the executable code, which I personally don't have).
2. The Alliance as a separate faction without any undead - what is meant by this? As far as I know, in "Rise of the Phoenix," the Alliance is replaced by the Free Cities, and there is no undead there. In "Chaos Theory," it's a reskin of the Alliance with the replacement of several units with new ones, and there is no undead there either.