WMG / The Mighty Ducks

The films:

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.

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.
  • It also explains why most of them have family surnames instead of the more common Icelandic patronymic last names.

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.

Charlie's mom got divorced between D2 and D3
In the second movie, Charlie spends a lot of time away from home because his mother remarried. In the third, there's no mention of a stepfather and it looks like they're still living in the same situation with her working at the same job. So Charlie's got a chip on his shoulder because of another Disappeared Dad and is especially resistant to change.

Lewis, Bombay's driver, is also an AA Sponsor or sober companion
Ducksworth hired him as a driver but also wanted to get Bombay on the wagon and figured out a sneaky way to do it. It explains why Lewis is still with Gordon and the Ducks even though he's no longer on retainer for the firm.

The animated series:

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.
http://tvtropes.org/pmwiki/pmwiki.php/WMG/TheMightyDucks