This is just the usual realignment made up scenario kinda crap.
So I am assuming UMASS and the current football only schools stay that way . So twelve for football and eleven for basketball.

Most likely the SBC will not get raided in the future.
I know it is possible but I am also assuming that to be the case.

That leaves three affiliate football and two non football members. No other FBS conference has non football members . That will probably become undesirable at some point. Twelve all sports members is probably the SBC long term goal.

The non football schools would be given the option to add football its a lot easier if an FBS conference invite is in hand. The best possible travel partner for APP ST will be ready in eight years.

So how could the SBC get rid of the football only schools in a positive way. Have each of the twelve members play one game a year against one rotating home and home . So instead of a nine game conference schedule an 8 plus one schedule. These games played in November and December would make an independent schedule to work. The newly independent schools could also play each other for six guaranteed games to schedule around.

Lot of moving parts the Sun Belt could even include the independent games as part of its TV package. Maybe more minor rules changes would be helpful like independent schools getting a full play off share. The SBC gets its tight footprint and retains some exposure and relationships with the outlier programs. The football only members get to remain FBS and play in Olympic conferences that make sense.