Here is how they sat at G H W Bush’s funeral:
Trump, Obama, Clinton (assume Geo W was with the family), with current on the aisle and down the row with latest to oldest. VPs in the row behind.
They could have done that at Carter’s too, with Harris and the VPs behind.
Here’s how they did Reagan’s
Yet a different order but still current pres, then the VP, then Clintons (next past)
Next row George HW (and Reagan’s VP), Carter, Ford
Both have the most recent former president on the aisle after filling the row in front.
So yes, I think the row behind Biden should have been Trump, Obama, Bush, Clinton not the other way (the way it was, Clinton, Bush, Obama, Trump).