I should take into account the numbers of players by team in each tournament.
The 1v1 tournaments are harder than the 2v2 tournaments, who are harder than the 3v3 tournaments and who are harder than the 4v4 tournaments. In this way, it will be more logical to win more points in the 1v1 tournaments than the 4v4 tournaments.
So I will use this sytem for the points :
4v4 => 20 pts, 10 pts, 5 pts, 1 pt (x1)
3v3 => 40 pts, 20 pts, 10 pts, 2 pts (x2)
2v2 => 60 pts, 30 pts, 15 pts, 3 pts (x3)
1v1 => 80 pts, 40 pts, 20 pts, 4 pts (x4)
Post here if you have other ideas.