Tournament rules for "One for All".

Anyone who thinks 4 is better than 3 should immediately suggest what to do in the playoffs if the score is tied 2:2 in the decisive game.

From the organizers' point of view, 3 is preferable – the tournament is better structured.
From the players' point of view, 4 – the inevitable difference in skill is leveled out by the brackets + more people can participate.

But in the playoffs, you could play like in the Davis Cup, 5 matches, but in a different order – pairs within their own brackets and 2 on 2, which is played if necessary.

Pros: 2 on 2 with random Castles – this hasn't really been done before (by the way, there's nothing wrong with random Castles, you just need to approach restarts differently).
One replay instead of 4 games.

Cons: Some of the captains may not be fans of 2x2, but this will become clear when discussing the proposal, but it is quite possible to take this moment into account when picking players.

And in general – the tournament is a team event, and 2 on 2 is the embodiment of teamwork, and I think fans will like it more