There should be different pairing system if number of players is low (>10). In such case the waiting time between games is too long, it must be reduced.
Also pairing sometimes is not logical. Example: played in a daily arena, waited 5 min. for a game, when other players finished (2 games), came to lobby, but started with each other another 2 games, and I had to wait again.
Also 2 players should be allowed to play again more than once in a row if they are the only players that remains in tourney. Example: 20 min. to the end, all players withdrawn, only 2 left , but they are not paired, so the time is just ran out without any games.
