Good Idea.
I purposed something similar to this for the Heritage Bowl a while back, but it entailed each of the non-participating schools each asking their alums to buy out a block of 2000 to 3000 tickets (say, 30,000 seats divided by the number of schools in the SWAC and MEAC). Each school would keep the proceeds from their ticket sells as their "conference cut" from the Heritage Bowl. The participating schools and promoters would have been responsible for selling out the other 30,000 to 35,000 seats in the, then, Georgia Dome.
A similar approach could be done with the schools using the season ticket concept and with alums for those tickets not sold through season ticket holders (if buying SCG tickets is an option). Let the proceeds from the SCG ticket in each package stay in the schools coffers as their "conference cut" (the concept similar to schools who go to bowl games: each school in the conference gets a cut of the bowl payout that the particpating school got). Each school gets the same allotment at the beginning of the year and if they sell them out, good. If not send them schools participating in the SCG in time for them to sell to their backers. I don't know how large Legion field is but if it seats, say, 70,000 then take 30,000 to 40,000 of those seats at the beginning of the year and divide them up over the 10 SWAC schools to include with their season packages or for sell to their alums as gametickets or donations. The other tickets would be held for the school's participating in the game each year.
I'm basing this on one key assumption; that being that the seating for the SCG is first come first serve. I was at the first SCG and I seem to recollect that that was the case. If its not, then correct me. But if the seats are first come first serve, then pre-selling them as a part of each school's season ticket package won't have an impact. If seating is reserved at the SCG, then as has been stated earlier, the logistics of this plan would need working.
But the idea is a good one, and I believe that its an especially good one if schools know that ticket proceeds will stay at their schools. For the SWAC, the game could be a sell-out, or very near one, paid attendance-wise even if the game crowd wasn't that big. At least all of the schools could potentially reap some finanical benefit from it.
Regards.