The output should be an array of ranks for each team, not an array of teams for each rank. So the array [4, 4, 6, 3, 1, 2] means that the rank of Team 0 is 4, the rank of Team 1 is also 4, ..., the rank of Team 5 is 2.
A team, which has not played yet, got 0 points, 0 goals scored and 0 goals conceded. But with these stats the team can still be ranked.