The second tournament for Heroes of Might and Magic II!

A few words about the result and the possibility of a better walkthrough.
As can be seen from the walkthrough, the map is completed relatively easily in 8 days.

No need to be modest :)

Therefore, the question arises: is it possible to complete it faster?

Probably, yes. For example, in seven days, if you break through the zombies in the right part of the map, between the Barbarian castle and the center.
In six days? I don't know...
In less than six days? I'm not very sure. And I won't believe it until I see a detailed description with saves at the end and beginning of each day.
I have nothing to say about four days. I don't understand how this is possible.

Let's turn to theory.
If the first hero earns money (together with the 1000 from the castle) in the first two days, totaling 2500, then on the second day you can buy a second hero. It's realistic!
On the second day, the second hero, together with the first (assuming there are moves left), should break through some chest (take the money) and preferably break through a gold mine so that on the third day you can buy two more heroes.
Because if there are not 4 heroes on the third turn, then even theoretically it is impossible to complete the map in 5 days.
+ if you start towards the Barbarian from the third day, you won't be able to take him!
On my third day, the Barbarian builds ogres and leaves them in the castle. I barely broke through them!

I tried to take castles with empty heroes - it only worked with the Sorcerer and Necromancer. And even then, I had to take 4 bores with me, because the computer immediately rushes back, and the castle cannot be held even with 3 bores.

When trying to rush to the Knight first, he turns around and has to be bypassed. The result is that the castle cannot be taken in 3 turns.

The Necromancer doesn't count. He is defeated easily, we leave him for a snack.

Added 19 minutes ago
If possible, in a few words about my progress day by day (I don't remember very well, so it's approximate):
1. I collect money
2. I buy a new hero, with whom I break through the right gold mine
3. I break through the right passage to the Barbarian. I don't go to the castle, because the angry Barbarian immediately attacks and defeats the hero. Therefore, I stand outside the range of the Barbarian's move (I delay for 1 turn).
4. I barely capture the Barbarian's castle, I have to defeat the remaining ogres. In principle, there is money to buy another hero, but I have to build and buy trolls and stay in the castle (I delay for another 1 turn), defending myself from the furious Barbarian. At the same time, I take the second gold mine.
5. I run to the Sorcerer from the Barbarian. I defend myself in my own castle from the Necromancer.
6. I'm still running to the Sorcerer. I start running to the Necromancer.
7. I defeat the Sorcerer's castle. The race to the Knight begins
8. I defeat the Necromancer.
9. I run to the Knight from two sides, and I run away from the Knight from the third. He gathered troops and decided to attack me himself.
10. I defeat the Knight's castle, I buy a fresh hero, I transfer the troops and defeat the fleeing hero.

As you can see, the walkthrough is not ideal. In addition to the not very good algorithm, I had to lose 2 turns.