2019 SOS Rankings - Odd little site

Found a Site that claims that it builds its rankings off of an aggregate ranking from other sites. It doesn't LIST those sites (and somehow these aggregate sites have OSU number #1 with an average ranking of 1.8, LSU #2 with an average ranking of #2 - which means that for every #1 ranking, there's a #3, or such for LSU - I can only imagine a lot of sites did not bother with post-playoff rankings to account for it).

Anyway, an interesting method of doing SOS was, because they rank every team, is an average rank of all opponents. This includes post season foes.

So, for example:

South Carolina had the hardest SOS, facing an average ranking for their opponents of 36.83.
Auburn was second, with an average ranking of 41.10.

Playoff teams were (this includes their playoff games):
#4 SOS Ohio State (42.09)
#10 SOS LSU (44.67)
#12 SOS Oklahoma (46.23)
#51 SOS Clemson (59.08)

The nice thing about this methodology is that we can see where the teams would stack up without their postseason boosts. Clemson obviously benefited the most from these bumps:

Clemson pre-playoff: 67.9 (69th equivalent SOS)
Clemson pre-ACC title game: 70.4 (71st equivalent SOS)

Prior to the postseason, Clemson's SOS was below the following G5 teams that failed to make the postseason:
Connecticut
USF

Others that had tougher regular season schedules:
Utah State
Memphis
Cincinnati
BYU

Which means that if Memphis had won their game against Temple mid-season, they would have had a better resume than Clemson.