Criteria for promotion:
1. Winner of the finals.
2. Non-champion team/s with the best regular season record compared with other leagues
Let's take Division 2 as an example. 5 slots in Division 1 will be opened for the promoted teams, that means the 4 Division 2 champs and one more team.
To determine which team it is, we will compare the regular season records of all non-champion teams in all the 4 leagues in division 2. Whoever has the best record gets promoted.