From the video

Video: Top 50 Week 9 Running Back Rankings + Tiers
The E tier, Jordan Mason and Aaron Jones, it's just like a really, really, really good defensive matchup for them against the Buffalo Bills. The issue is neither of these guys are very good.
Mentioned at 20:46 – 21:12Captured by STACKED 47 min after posting

STACKED’s take

Negative signalMatchup

Great matchup vs. Buffalo but not a quality player; KOC offense limits RB upside.

Ranked in E tier by Mattek Fantasy Football. Has a really, really, really good defensive matchup against the Buffalo Bills, but the source acknowledges Mason is not a high-quality player and the KOC offense has been consistently bad for running back expected points regardless of quarterback.

Jordan Mason headshotJordan MasonRB · MINPlayer page — value, ADP, projections, and every insight