What you are missing is that there needs to be a national team to compete at world level.
Take rugby, for example: provincial sides play their season and the national team is selected from these local teams.
The provincial series in New Zealand is the Ranfurly Shield. This is akin to your 'world series'
The national side competes in international competition for world events ie: the 4 Nations, World cup, Bledisloe cup. This is akin to the Baseball World Cup.
There's no way New Zealand could have regional teams competing for 'world champ' status: that's just absurd.
The whole point I am making is: claiming world champion status from local provincial teams playing each other is really silly.