The dumb AI ruins all the enjoyment of the game. The other day, I was testing the new Quantomas mod, and it's a completely different game with its AI. It's become very difficult to play against; it casts mass spells, which aren't present in the vanilla version. It uses the correct build order for its faction, which the vanilla AI doesn't do. If it needs to play defensively, it does so, whereas the vanilla AI almost always attacks aggressively. And most importantly, the AI doesn't cast single-target evasion spells throughout the game until it puts it on every unit.
But again, not everyone can handle a strong AI. Personally, on a couple of my favorite maps, I played as Kaspar as usual... the current AI from Quantomas defeated me much faster. However, on NHF 0.89 (I haven't tried 0.90 yet, unfortunately), I defeated all the NHF necromancers that were specifically set up to challenge me...

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Неудачное планирование ведёт к неудаче ...
NCF - мод, добавляющий дополнительных существ в HeroesV 3.1