I'm not going to go back for the numbers, but its not true we give up 8 less, at least when comparing games against P5 teams.
Obviously all these numbers are small samples, there are other moving parts, etc. (I also haven't looked before making the post, so let's see what they say!)
J. Williams debuted on 2/3 against Michigan.
Stats comparison from season start through 2/2 vs 2/3 to today (before / after):
Record: 10-10 (2-7) => 5-7 (5-6)
Adj Off Eff: 97.3 (#311) => 100.0 (#275)
Adj Def Eff: 90.9 (#6) => 92.7 (#7)
Barthag (T-Rank's overall rating): .6867 (#103) => .7055 (#100)
Effective field goal %: 43.4 (#357) => 43.6 (#353)
Defense EFG%: 46.3 (#31) => 48.8 (#106)
Turnover rate: 17.1 (#161) => 15.7 (#134)
Defense TOR: 21.6 (#21) => 21.8 (#10)
Offensive rebound percentage: 31.6 (#97) => 27.8 (#190)
O REB% allowed: 31.3 (#267) => 31.5 (#296)
Free throw rate: 34.8 (#129) => 29.7 (#249)
Defense FTR: 31.5 (#152) => 39.3 (#301)
2P%: 43.8 (#349) => 43.5 (#344)
2P%D: 45.8 (#36) => 46.4 (#48)
3P%: 28.4 (#344) => 29.3 (#328)
3P%D: 31.4 (#50) => 35.1 (#217)
3-point rate: 33.1 (#281) => 29.1 (#332)
Defense 3PR: 39.6 (#262) => 39.2 (#235)
Adjusted Tempo: 69.1 (#157) => 68.3 (#135)
Wins above bubble: -2.4 (#102) => -1.0 (#90)
For raw stats do keep in mind that the before part includes non-conference cupcake games.