I think the point of the picture was trying to provide a hypothetical selection based on fairness that flat out doesn’t exist.
For an at large berth (non-conference winner), I’ll double down that the answer is 12 RSW wins needed for an at large berth - for any team non P2 and not entering the season in the top 25 popularity contest.
Betting markets aren’t perfect but it’s closer to reality than typing words on the internet. Of the 12 teams with shortest odds to make the playoffs, 6 are SEC, 4 are Big 10, ND and one ACC. (And the 13th team is SEC too).
There is a difference between preseason polls and end of the season. SEC and Big 10 will always get the bulk of the preseason hype. But almost always some are overrated and they will fall out of the Top 12. Primarily because there is such a bias to do preseason rankings based on how teams finished the year before (as a case in point, 9 of the top 12 2024 predictions ranked in final top 12 in 2023 in bold - 3 new are Notre Dame, Penn St and TN who are all favorite children). By the way, the 3 who finished in Top 12 in 2023 and not in 2024 are all ranked in Top 18 for 2024. So where you finish has a huge impact on next seasons pre-season ranking even though with NFL draft and transfers teams normally have a lot of turnover. Which is the reason no rankings should come out for several weeks (which will never happen due to the hype preseason rankings have for rabid college football fans).
Here is one poll preseason for 2023:
1 UGA, 2 Michigan, 3 Oh. St, 4 Alabama,
5 Penn St, 6 LSU, 7 FSU,
8 USC, 9 Washington,
10 TCU,
11 Utah,
12 TN
Final AP 2023
1 MIchigan, 2 Washington,
3 Texas,
4 UGA,
5 Alabama,
6 Oregon,
7 FSU, 8 Missouri,
9 Ole Miss,
10 Ohio St, 11 Arizona (3 losses),
12 LSU (3 Losses)
So they missed on 5 of the 12. And that is probably normal. Based on this final, 12 team playoffs in 2023 (using 2024 conference affiliations) would be SEC 6 teams, Big 10 4 teams, ACC 1 team, Big 12 1 team. So though the mix definitely changes the reality is the Big 2 is still predicted to dominate as stated above.