I don't think you're reading that right

he means the ACC champ will be at least fifth out of the top five ranked conference champions. So, it could look like this: #1 SEC Champ, #2 Big 10 Champ, #3 Big 12 Champ, #4 MWC Champ, #5 ND, #6 Big 10 runner up, #7 SEC runner up, #8 Big 10 3rd place, #9 SEC 3rd place, #10 Big 12 runner up, #11 Big 10 4th place, #12 FSU (ACC Champ), with #5-#8 hosting games

ND can't be in the top 4 and in this scenario, even though FSU might not even be ranked in the top 12, they'd get the #12 slot as an automatic bid because they are the fifth highest rated conference champion. Where this falls apart is if FSU is ranked below 2 conference champs that are outside the SEC/Big 10/Big12. So if 2 teams of the following example group win their conference and are ranked ahead of FSU as ACC champ, they're probably out: Liberty (Conference USA), Boise State (MWC), Memphis (AAC)