If you already have such thoughts in your head, even playing the game in one go won't change them. In that case, you should play with trusted people or play a different game, because in Heroes, no one is immune to cheating. And playing in one go is nonsense because not everyone has the time to play non-stop.
Tell me how to play in a tournament with a trusted player, and not with someone who was randomly assigned. :D
The problem of cheating needs to be solved, not just dismissed as unsolvable.