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The idea of rebalancing and reorganizing the neutral creatures into a new, unified list is good and correct.
However, in my opinion, many creatures from the current neutral creature sets should be cut using Occam's razor. No offense, but I don’t think there is any need for several dozen creatures that are unremarkable either gameplay-wise or visually. This is one of those cases where more does not mean better.
I believe that when dealing with such things, you should ask yourself: "What interesting and new features does this creature have?" "Does it look interesting visually? Does it have gameplay value?" "Is it really needed in the game? Is it superfluous?" Too much monotonous content is also bad. Players simply get tired of 20 hastily recolored minotaurs, and few will want to delve into the nuances and remember what the difference between them is.
Otherwise, good luck with your build; it will be interesting to see what you come up with.
If you need them, the models of creatures that I ported from Heroes 6 and 7 are at your service. Just please, if you decide to use them, read how I asked to use resources from my mod and do as I ask. That is, copy the archive with the "clean" resources to your mod without changing or renaming anything, and then make changes on top of that. If something comes up, feel free to contact me, and I will try to help.
In general, there are never enough good, interesting, and balanced creatures. So that a creature isn't just added for the sake of adding it but is actually appropriate. Therefore, it’s interesting to see what ideas you will come up with. Maybe some cool gameplay idea will emerge.
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In general, for such a thing, it would be nice to somehow update the neutral creature list. Many players don't see any value in them because they are simply neutrals. It would be great to give players the opportunity to regularly control these new creatures without replacing the original creatures from the castles.
I have already described the method using alternative buildings for hiring in cities; it works quite well.
/topic/at/1009839/
However, it is unclear how the AI will behave with this method. It is possible that it will become extremely unintelligent. I will try to create a working demo and test it in the future.
By the way, if anyone knows scripting and wants to help, I would be very happy.