Most interesting "gimmick teams" would be splitting Canada in Three Teams.
Team Quebec
Team Ontario
Team WHL
Split the players in terms on which CHL league you were drafted as a Canadian. Or if you wasn't drafted, then the area born.
I'm not sure if this would draw any interest for Canadians, but it would give some Memorial Cup All Star feelings on the same tournament, when these guys play against each other as adults.
When I looked some basic data, Team Ontario and team WHL Canada would be two top teams in forward scoring power, just sligthly better than USA. Sweden would be 4th best. Then Quebec would be at level of Finland/Russia.
You can build ~17 different Team Canadas from NHL players, so I think that's the way to go, rather than put some put European small countries together.
And I wouldn't give a team for Switzerlands, Germanies at all. They just won't have enough players and World Cup during a season affects on European Leagues. The permit to have a National team would be that it has to consist NHL players only, and if your Nation hasn't produced them enough in NHL, then you won't participate.
CAN, USA, RUS, SWE, FIN and CZE fill these standards.
Quebec vs. Ontario? How would that feel?
Group A
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Team Ontario
Team Quebec
Sweden
Finland
Group B
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Team WHL Canada
USA
Russia
Czech
To draw attendance, build groups this way. Quebec pulls full home crowd at Quebec/Montreal, Ontario pulls full home crowd at Toronto. Put WHL Canada play games against Russia and Czechs in Vancouver/Edmonton/Calgary.
USA plays in USA major cities, Chicago/New York etc. Sweden-Finland in Toronto. Russia-Czechs in Madison Square Garden.
It's business. Maximize the people's interest. Maximize Canadian interest. It's still their game.