A few tips on installing scripts.
A script with a post-event.
This type of script was quite common in Heroes IV, where a message would appear after a battle (i.e., the script would continue). But how do you make it work in Heroes III so that after defeating a monster, a message like "You are being attacked" appears, and the battle continues? The monster guards the adjacent cells, so when a hero attacks the monster, the event placed directly in front of the beast will not be activated. After the battle, the hero will end up on the cell with the event and activate it. Why is this needed? Of course, to add variety to the game. Imagine, there is an Azure Dragon in front of you. Let's say there are three free cells separating you. In the second cell (from the dragon), we place an event with text stating that the dragon will only join the hero's army if the hero can defeat it. We attack the dragon. The event that was placed directly in front of the dragon will contain text stating that the dragon agrees and will join the army, and in the "give creatures" field, we select one Azure Dragon. Thus, before the battle, the event will be inactive, and after the victory, you will have your dragon at your disposal. This trick can also be used under the condition of defeating a specific monster, when before the end of the scenario, a message like "The monster that terrorized the area has died at your hands" appears, or you can create another battle with its minions.
And here are a few more nuances:
1) The script with the attack should be placed where it is logically expected, for example, on enemy territory or in front of a mine; again, you need to hint that an attack is expected.
2) It is not worth creating events where the player is attacked by legions of level 7 creatures, again, unless there is a logical reason and a small hint.
3) A pit does not block the player's path, so you can place an event with a small reward on it, for example, in the form of gold.
4) If the desired artifact is in an invisible event, then you must definitely indicate the location of the search.
I brought all this up because I have encountered similar maps more than once. You walk along, not bothering anyone, and suddenly "You are being attacked by 1000 demons!" Or, I played a map a long time ago where you had to find an artifact, but I could only find it after looking at the map through the editor.