So, each player has to take 8 of something, one from each division. You can take 8 QBs, or you can take 8 TEs for example.
Gryffindor gets to take say 6 QBs and 2 RBs on one team and 6 WRs and 2 TEs on another.
In this example, the first Gryffindor would be counted as a player selecting QBs in the potential multiplier.