From what I've read (you know, only radically-slanted leftist rubbish), it would just be a general scheduling thing.
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So I'm guessing it would have the goal of making sure each conference has full schedules and that the top programs always have a "big-boy" OOC team scheduled, for good optics. If they were smart about it, they'd mostly halt the ebb and flow of sometimes strong-sometimes weak schedules and make them more consistent.
Also, if they were really smart about it, they'd agree to schedule-share their underling teams as cannon-fodder for the other conference's power programs so that those teams get as many wins as possible.
I'd put teams into one of two pools: pool A (Clemson, OSU, Oregon, etc) who have 1 team from pool A scheduled every year and have 2 from pool B (the others) to maximize wins.
But this whole coalition could be something more. I'm just thinking out loud here.