In FM 2012 or so really strange things happened in season 2: West Ham won the Premier League, and Bologna won Serie A - in the same season. Fulham went from PL to National League after 10 seasons or so.
About Rosenborg, it's common in my saves that they get relegated after 2 seasons or 3. May seem unrealistic, but this season they're only 6 points above the qualification place, and 8 points above relegation. So it may happen irl, however there are only 6 games remaining so they will probably stay up.
In FM 2012 or so really strange things happened in season 2: West Ham won the Premier League, and Bologna won Serie A - in the same season. Fulham went from PL to National League after 10 seasons or so. About Rosenborg, it's common in my saves that they get relegated after 2 seasons or 3. May seem unrealistic, but this season they're only 6 points above the qualification place, and 8 points above relegation. So it may happen irl, however there are only 6 games remaining so they will probably stay up.