Regarding that particular type of tournament...
Actually, I see two ways to organize them:
1. A truly "non-commercial" tournament, the results of which would not affect "reputation" and would not be permanently recorded on the website... In other words, people would play to:
a) enjoy the game;
b) so that everyone, for a certain time (the duration of the tournament), can see that they are presenting themselves as "fair players," which, in turn, is a kind of temporary "reputation"... i.e., the issue of motivation is not overlooked...
Getting (online) enjoyment - when you agree with a decent opponent to have a duel - it's a normal friendly, but official game!
Getting (offline) enjoyment - sit down in the evening, set up a map and opponents - and go for it!!!
P.S. Then why go to the forum - create topics with a new tournament - impose the same rules on everyone - and the same map (starting save)?