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

Yes, I meant trigger events. Because of them, it's impossible to create a normal scenario.
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And I would also add more monsters and the ability to upgrade them.

Trigger events are a very convenient thing. Essentially, they are the initiator of a created event. They are triggered by a specified action. That is, unlike calendar events, trigger events may not occur at all in the game if the player does not fulfill the specified condition. There are many conditions in trigger events.

I don't understand how the presence of trigger events can prevent creating a scenario? At worst, you can simply not use them :)

Regarding monsters. More new monsters would be good, but upgrades are unnecessary; monsters in Heroes 4 rarely take center stage in the game.