Yes there is a way. Alabama beat WVU, and Auburn beat K-State and these are 2 of the top teams from the Big12.
Played on the field and all that jazz.
Basically, what you are wanting to do is punish teams for being in tough conferences and reward teams for being in easy conferences with easy play off births. The majority of time it will be conference champions by default, but if it isn't - there is a reason for it.
Marshall has not been beating people soundly, they were losing against FAU this past week until 3 minutes left in the 3rd quarter and didn't put them away until middle of the 4th quarter. Meanwhile, Alabama played FAU and won 41-0 and had backups in during the same time that FAU was winning against Marshall.
Then lets just do away with any notion of playing for a title and just let four SEC teams play a "playoff" as CLEARLY the top four SEC teams, hell, the top eight SEC teams are better than the champions of ANY other league, we all know UK would win the B12, ACC, B11, and PAC??, right?
Marshall is winning 46-16 on average, pretty soundly winning, if you ask me. What YOU are doing is unfairly punishing good teams for playing in a weaker conference, ALL conference champions deserve a shot. If you want to be in the playoff, win your league, nothing at all unfair there.