It looks as though in this discussion, statistics are being used in two different ways. One is trying to use cumulative offense & defense ranking for the season, the other is using numbers from the championship game (goals allowed). I do agree with the point that statistics as well as a teams record can not be used to compare or rank teams in this sport.
The argument that the team that plays the best defense in the championship game or holds their opponent to fewer goals than they normally score sounds like a solid argument.

You lose all credibility with your ad hominem attacks, they signal that your argument is weak and not based on anything other than you opinion. You have also identified yourself as the type of person who makes this sport so toxic. In the end, the team that wins will most likely be the team that gets great goalie play, plays great defense (including the Mids), re-defends well and controls the middle of the field (in transition and on the draw).