I agree with you. I think Creighton is a top 25 team, and Marquette is borderline/probably not top 25, but definitely top 50. And you're right that most analytical ratings agree. Creighton is #25 in the NET, #22 at Massey, #22 at Her Hoop Stats, and #16 in ELO rankings. They have more Q1 NET wins than we do...and many of their same starters today led that team to the elite 8 just two years ago (e.g, 4 of their current starters played 23 minutes or more in their upset on Iowa's homecourt in the 2nd round).
Marquette is #33 in the NET, #32 at Massey, #34 at Her Hoop Stats, and #39 in ELO rankings. Their non-con SOS was 223rd in the NCAA so their early wins and NET rating were probably inflated. That win over Illinois looked a lot better at the beginning of the season when everyone thought Illinois was a team on the rise and would be a solid top 25 this year, and now they're 8-10.