Is #9 the highest ever for a 4 loss team?
I didn't really think of this when you originally asked but it is amazing how much this concept has shifted due to structural changes in CFB over the past few years.
~50 years ago (1968) Ohio State won a NC with a Rose Bowl win at 10-0. In that era the Buckeyes typically played nine scheduled games and then the Rose Bowl (that was the only bowl for a Big Ten team then) only if they won the conference. It wasn't realistically possible to win the conference with four (or even three) losses so a four loss season meant 5-4.
~40 years ago Ohio State typically played 11 scheduled games and bowls other than the Rose were possible but still relatively unlikely. It wasn't likely to get a bowl invite at 8-3 so a four loss season generally meant 7-4.
~30 years ago Ohio State typically played 11 scheduled games and a bowl was highly likely for a 7-4 or 8-3 team so a four loss season generally meant 8-4.
~20 years ago Ohio State typically played 11 scheduled games and a bowl was a given for a 7-4 or 8-3 team so a four loss season meant 8-4.
Starting seven years ago Ohio State played 12 scheduled games with the possibility of a B1GCG then there was also the fact that with the BCS and later CFP it became possible that a non-Champion Ohio State could get an elevated bowl as a replacement for the B1G Champion if said champion made it to the BCSCG or later CFP.
Texas this year is a perfect example of all of these things. They had 12 scheduled games including a "neutral site" OOC game in their opponent's back yard that they lost (Maryland) then they lost two conference games to good teams by a combined four points. Then they had an extra game, the B12CG where they lost their rematch to a CFP-bound Oklahoma by 12. Then they got an elevated bowl because they ended up being Oklahoma's replacement in the Sugar Bowl. Prior to the CFP, Oklahoma would have been in the B12's Champion bowl and Texas would have had a lesser opponent but due to Oklahoma's CFP bid, the Longhorns got a better Bowl opponent and thus a better opportunity to prove themselves and improve their ranking.
I think 10-4 with wins over Oklahoma and Georgia and three close losses deserves a top-10 ranking but it is odd to see a "4" in the loss column when looking at the top-10.