The scheme is perfect for spread O teams.  It does a great job in coverage and in limiting space those teams want to attack.  But when we play a run first more power team, we don't adapt much.  We still run the same concepts generally.  Especially with the backers being 5 yards off the LOS and stepping backwards first.  Lined up in the same spots, little to no stemming, no showing different looks hoping to confuse a QB. Who does that anymore?  They do not play downhill well, and against a run first team that does not make sense.  Again, with  spread team, it does.   So adapt.  Attack gaps.

The other issue is the DL and how poor that unit is. Tuiaki has been DC since 2016, DL coach since 2018.  That is his unit, and t hey get worked far too often and their technique often sucks.  This could be a conversation in and of itself and I could go on here, but this unit which he oversees has been poor.  Last year they were the weakest link on the team and got manhandled way too often.  After 4 years as the DL Coach, not many excuses to be had.  And as DC, it compounds it.

Those are my main complaints.    So part is personnel for his unit, part is scheme rigidity.