I see the winners of each of the 2nd round tournaments are listed as the co-willers of the cup? Isn't there supposed to be a following round where those three face off?

The winners of a round appear there until the next round starts. Then they disappear until the round finishes. It's a minor glitch of golem but it is sometimes helpful to see the winners of a monthly cup round.

Would be nice if the final group gather more than 3 players. In case that a round has less or equal then 3 groups in the next round can advance the first 2 places from each group. This way you can have a maximum 6 players group.

That would've been nice for me (I finished 2nd in my section) but I think it's better the eay it is. The foloks who finished first earned the right to face limited competition.