The rational on Cincy is that you couldn't put them in the top 4 and then drop them out if they don't lose. I mean you can, but it would cause more consternation than putting them at 6 did. Putting them at 6 allows for the situation where chaos ensues and the B1G beats each other up, OU collapses, and Ore loses 2 more games. You can then move them to 4 when they win out on their easier schedule.
Or, the committee is going to value a bunch of 2 loss teams that played tougher schedules. In that case Cincy's only path is a 12 team CFP but they will probably suck by then like UCF and Houston before them.