Red dungeon, high chance of starting at the top, no +1 speed from native terrain, weak starting army – a huge temptation to switch to Necropolis if it appears. The point of the tournament is to determine which hero is better, not to read reports about Izra defending against Shakti, or Shakti defending against Gosh.
It is impossible to completely eliminate switching to another hero (for example, Tiaz arrives, the skill tree is better, etc.), but fixing Necropolis will at least alleviate this problem.

I have a different opinion. I remember that there used to be debates about who was better in Chaos rules, Valya or Katya. Of course, no one was going to level up Katya; the question was purely methodological – which hero is better to start with. Similarly, later in TE, there were discussions about whether to start with Anna or Nila/Iona/Toros. I also remember that at one time, it was fashionable to start with Ramp through Yenova, although sometimes she was even made the main hero. So, here, the start with Gunnarr is compared to the start with Shakti under certain conditions. Of course, the conditions should be as close as possible to real games. For this reason, I am against restrictions that do not exist in standard tournaments. Regarding the color – in my opinion, Gunnarr should not be strictly given red, but the ability to choose a color. On some maps, blue will be preferable to red.