Because of this system, we won 3 gnw's in a row, there are only 2 groups at our server, the first one has 2 times more members, yet still we are winning.

quality vs quanity. It's one thing to fight a team with a bunch of members, its a different thing to fight a team with a bunch of strong members. With the previous system, those strong players had to be spread out since they're were more lands to take into account. Now that there is only three, they can just load two lands with all they're strong players and win. There is no strategy anymore.

If I'm not wrong you need at least 27 participants to unlock the 6 lands.

I personally prefer the 3 lands because I have a small number of active players in my group, and we're all decently strong, but imagine like 10 people fighting in 3 lands, so 3 people per land each, and the chances of losing are high.

It's not like my opponents are terribly weak, similar power, just that we know how to counter them.

Opinions will differ from server to server. Dead servers need the 3 lands instead of 6.