The second stage of the "Van Kanighem" tournament.

Initially, all heroes in the second game start at level 1.
You cannot buy a hero with a level higher than 1.

I agree with this – understood!

It's also easy to check the +5 bonus using save files.

But I disagree with this. Are you sure that a player from a tournament a few editions ago, who placed 6th, didn't use this +5 trick? Who checked his save files? At most, they can check all the weekly save files of the leader. No one will bother with the rest. Because it's easy to check a single player. But checking all participants would require significant effort, and each player would have to send in not just one save file, but one for each week. So, this ban doesn't make sense.

Added 3 minutes later

Why? Explain it to me, I'm not very bright....
In all tournaments, for other versions, there are no such restrictions....
Sincerely.

Well, it's like you're a cool hacker and you create the most powerful hero possible, and then you say you bought him in the tavern :) How can Alan tell in this case whether you bought him in the tavern or not? But as it is, they just ban it, and that's it – but you can track the leveling up of your heroes. On the one hand, it's correct, but on the other hand, it limits the possibilities of the game