Americas Stage 1 Format?

How come some teams play 5 matches and some teams play 6?
And not everyone plays each other once...? Whats the purpose of Alpha and Omega brackets lol

Edit: Guess all Stage 1 formats the same. Someone explain

Some teams play an extra game due to the 13 teams and I think everyone does play each other eventually since the format for stage 2 is alpha vs alpha instead of alpha vs omega like it is rn

Americas have 1 team miss a game per week whereas emea and cn have 1 team play twice a week. Idk what’s up with pacific but there are 2 super weeks straight up so they finish a week early

smartest canadian