I didn't like the fact that the AI generates armies for free, as a derivative of the game time. This turns everything upside down. The most formidable opponent was the Necromancer, and the easiest was the Dark Mage. The Titan was swarmed by everyone, an incredible beast. Dugald broke through the gates, and the Necromancer captured the Castle. The Dark Elf hero was first attacked by the Demon hero, then by the Dwarf hero, and only then was Dugald able to defeat him (all battles in one day). As a result of this troop generation, the Necromancer looked very ridiculous, leading a huge army of undead from the Dark Elf Castle (he had no other).
The other side of the same coin: prolonging the game leads to a loss. And the higher the difficulty level, the longer it takes to build up armies, i.e., the higher the probability of losing. (The map is practically "tailored" for the Dark Elves.) The condition of holding your own Castle leads to prolonging the game. It takes 7-8 days to go there and back, even with logistics, stables, and a "city portal." At least one AI hero will attack your Castle during this time, and only your own hero can defend against them. If you have already captured an enemy Castle, you need to be very careful when moving around the map, otherwise the "portal to the city" will not return your hero to your own Castle at the right time. Therefore, I have a suggestion: either the captured AI Castle should be destroyed, or the teleport should only transport you to your own Castle.
P.S. I almost forgot about Rupert. He's a suitcase without a handle; even at level 30, he took up valuable space in the shelter throughout the game.