Evidence that ENTIRE league draw has already happened

[Toxcatl]

20% quality reduction if you fail to promote
10% quality reduction if you promote

When you promote, the overall quality of the team stays the same. Players are not getting weaker in absolute numbers, only in relative, comparing to your new level. "Welcome to the next level, teams are stronger here, and your team is weaker comparing to them". Sounds logical. But if your rules are applied, players will get weaker if the team fails to promote. Weaker for real. I don't see the logic in this.
And what if I did my best, but failed to promote? I get my team even weaker than it was before. "Nice try, loser! Now you have to reach the same goal with even weaker team. Good luck, you're gonna need it!"