Apples to Oranges. Billy was coaching a G5 school so the talent pool he had access to was different than Riley and Brian Kelly as both of those guys have been successful P5 coaches with Playoff experience. That showed in guys they brought in year 1 via the transfer portal. So if you want to make it more fair, I would start Billy at Year 2 vs their Year 1 for a better comparison.
And remember that ND was throttled by Louisville last week, which was in turn throttled by Pitt this week ? How crazy is college football ?