To give some context: the plugin cannot implement all different rules for all competitions. FIFA has different rules than UEFA and both can be different from national competitions. The plugin does not know what kind of competition you are running.
I have some basic rules that apply to most situations (all based on data from the matches) and there are indeed 2 extra tie-breaking options available. One is the group order value on the team, but the plugin will only use that as a last resort (more on this later). The other is a complete overwrite of the order via a filter (to have your own custom rules).
By default the following sorting algorithm is used:
// total points for the team
// check if the teams have the same number of matches played
// check goal difference (difference between scored and against)
// then check the goals scored
// all failed, so we check a ‘hardcoded’ (set on the team) ordering
If you do not see Mexico in third place, could it then be that you have an extension enabled to overwrite the default sorting? I know that I created something for the last UEFA European championship once.