How about option 6 ...
Invite one of your players to captain an 8.5 combo team. Explain to your squad that everyone can play 8.5, but you are going to invite a smaller group to come back for your 7.5 team if they are interested.
Go down the list until you have a full squad for the 7.5 team and let the others know that 8.5 is for them if they want it.
"You should be playing linebacker, not singles."