1 or 2 of those teams are almost elite major teams like Resmondo and Dan Smith quality.
There may be one other AA team in there also but nowhere near 21. Maybe more like 3.
The other 16 play A or B.
What makes the challenge cup great is its the offseason, team chemistry can mean more than on paper talent for that one weekend so anyone can beat anyone in a given game.
But the big names will most likely be there at the end like usual.