The other team got the home game advantage because they had more wins during the regular season than you (he has 17 and you only 15)
The scrimmage that has accidentally appeared for everyone at the same time is probably decided randomly.
If the BBs don't fix it in time do the following:
Put less than 5 players as starts - automatically forfeiting the game
OR
Put the other members of your team, that never get to see the light of day usually, in.