Gunnar and Scooter are Separated at Birth identical twins.Gunnar was adopted by an Icelandic family and Scooter by a rich American family. Their father may have been a hockey player and they both inherited his talent and passion for the game.
Frollo was reincarnated into Wraith.Both Frollo and Wraith love burning people. If Frollo got sent to hell, he could have became reborn as Wraith.
Team Iceland was made up of the best players from the hockey superpowers.Iceland in this film is Team USA's greatest rival despite Iceland not being a hockey country in real life. Also, the real hockey superpowers (Canada, Russia, Sweden, etc...) are hardly mentioned. Maybe Iceland somehow got the best players from those countries, making Iceland a hockey superpower and the other teams a lot weaker. Plus, people have commented that Gunnar's (played by an American actor) accent seems fake. Maybe he's actually Canadian.
District 5 was new.Never expressly stated but heavily hinted that "District 5" as it was in the first film was a newly formed team. This would explain their lack of team work, they never worked as a team together before that season. The lack of a team name and sponsor as well implies they have not had time to find one yet. The district map shown in the first film also has District 5 in the dead center, it is the smallest district and surrounded by at least five other districts. Most likely being the most heavily populated area they broke up the parts of the other districts created a new district and renumbered all of them. Banks seems to have played for the Hawks at least one season prior and it would easily explain why he was playing for them instead of District 5 for most of the season, he and his father along with the Hawks coach did not know the redistricting placed him on a different team. He just showed up for practice like he did the year before no one thought to ask this season which team he was playing for.