Has anyone a clue how the promotion and relegation works at team tournaments?

First let's look at TC history…
SSTC 1 standings: 1.Polska, 2.Slovakia, 3.Poland, 4.MonStars, 5.Italia, 6.Finland, 7.LSEspañola*, 8.Canarinha, 9.Romania, 10.ACanadianFHC, 11.AxonPro
SSTC 2.1 standings: 1.Polska, 2.Slovakia, 3.Italia, 4.Finland, 5.MonStars, 6.Canarinha, 7.Poland
SSTC 2.2 standings: 1.EdFrance!, 2.Entertado!, 3.Earthlings!, 4.España*, 5.Belgium drv!, 6.Romania, 7.AxonPro, 8.ACanadianFHC
SSTC 3.1 (ongoing): 1.Finland, 2.Italia, 3.Edfrance, 4.Entertado, 5.Canarinha, 6.Slovakia, 7.Poland, 8.Polska, 9.MonStars
SSTC 3.2 (ongoing): 1.Earthlings, 2.Romania, 3.ACanadianHFC, 4.España, 5.Belgium drv, 6.AsianST!

I took the liberty of abreviating some Teams names. “!” after a name indicates its a new team (I also took the liberty of not indicating “new teams” on championship 1). I marked LSEspañ and España with * because the latter is a smaller version of the former (it was probably considered as a new for promotion/relegation)

Looking at this history, it seems that:
1. There is a minimum of teams for more than one group (15 is enough for two groups, but that number may be smaller - first championship was played with 9 teams in a solo group)
2. The seven first (possibly 8) teams in a group are safe from relegation)
3. The two first teams in a group are up for a promotion
4. New teams enter at the bottom

Correction: there was 11 teams in first championship

*were

Apple PI got to very similar conclusions