Then who gets in as #7 and #8? Think #9 and #10 would say the system is perfect?
Now consider this scenario. GT upsets FSU, Wiscy beats OSU, and Arizona beats Oregon who gets in with an 8 team playoff?
There would be two 12-1 teams - Alabama and FSU; five 11-2 teams Oregon, Arizona, GT, Ohio State, Wisconsin; two 11-1 teams Baylor and TCU; and two 10-2 teams Michigan State and Mississippi State.
How is 8 any more perfect than 4 in that scenario?
Now throw in a potential undefeated G5 team or a guaranteed slot for the best G5 champion into the mix?
Still think it's perfect? No system is perfect and I'll let you in on a secret you may or may not know. It's not meant to be.
The system is meant to protect the P5, protect the regular season, to keep the G5 down, and to make the most possible in terms of $$$ while achieving those goals.
Cheers,
Neil