What would you change in Heroes of Might and Magic IV?

It's incredibly annoying that they merged Inferno and Necropolis... In all the other parts, they hate each other!! And Efreet and Nightmares suddenly ended up in the Demon's castle. Dwarves, everywhere they love mountains and snow (well, in the third part, they were neighbors with the Elves in the forest, but those were forest dwarves)), but suddenly they became warm-weather lovers and moved south to the Wizards in the desert... Ballistae... - this is just a complete disaster. Griffons went to the Elves - well, that makes sense, I never liked them as human troops. Some shooting hives and mantises... And mechanical dragons - also a complete mess... shooting units of the Necropolis - WHAT is that?? There were none of those in any of the series. The mages (units) are too weak. I don't like that there are Minotaurs among the Wizard heroes. What the heck are Minotaurs doing as mages (wizards)!? They are supposed to be commanders. I also don't like the heroes - Hobbits. Imagine a Hobbit hero, killing 10 black dragons with a single shot from a sling... And I haven't liked the Dwarf heroes since the third part. Yes, I'm a racist, I can't help it! The heroes - Imps, Zombies... also a complete mess. Orcs with pig snouts... And yes, I didn't get attached to any of the heroes in the campaign. The campaigns are generally weak.

It's a matter of taste. Demons and the undead became "irreconcilable enemies" starting with the "reboot of the series" in its fifth iteration (the world is structured that way there). I wouldn't say that's wrong, but it's not an "undisputed canon" either. In the third part, they had to be allies (the alliance with Nighon was initially intended to be a triple alliance, similar to the alliance of Erathia, Avlon, and Bracadia), and in the fourth... When building a new world, the developers were inspired by the "color" system from Magic: The Gathering, where both the undead and demons are black. From a plot perspective, which NWC ultimately lost (not without the help of "fans" who literally demanded the removal of sci-fi elements from the game), it's still quite justified. The Krigans are alien invaders, devouring world after world. In Erathia, a full-fledged "Colony" was operating (similar to the Hive Fleets of the Tyranids from Warhammer 40,000), and only a few outcasts ended up in Axoth (I suspect that the main forces of the Krigans successfully left the planet before the Cataclysm), for whom even survival became a non-trivial matter, and the Necromancers... In the original, the Necromancers didn't shy away from any means to achieve their goals. And demons are one of them.
Efreet fit perfectly into Chaos, as the opposite of Order Djinns. The question is rather why they were originally with the Demons in the third part (there are questions about many of the castle units there), and the Dwarves... they were "forest" dwarves to suit the style, and for me, they still looked alien (in Erathia, they had their own kingdom, which took the first blow from the Krigans and Demon Lords, who "dug out" neatly in the dwarven mines). And they did most of their business with the Wizards of Bracadia. In the fourth, the castles are distributed primarily not by state or "race," but according to worldviews. And Order suits the Dwarves best. As for the Minotaur/Hobbit/Dwarf heroes as mages, this has been going on since the early parts.