So he heavily relied on PFF group rankings to create this nifty chart based on last years numbers. I seriously do not think he is factoring in the mid tier adds teams have made because that would 1. take to long and 2. even if he did factor in mid tier changes... by the time he did it, there would be new changes.
Thus my personal opinion and belief is that this is a mix of last years pff scores with some of the bigger changes made so far this year.
Also might I add... The Off, Def, and Tot grades make little sense. IF you subtract the red rankings and add the green rankings the Eagles offensive ranks add up to 14.1. Do the same for the Cowboys and their offensive ranks add up to 8.2 and yet you go to the offensive rankings with 2.0 being the best, Cowboys Offense is 1.8 (.2 Difference)
Now lets use the same math concept he has going here with the Bengals. If you add their greens and subtracted their reds they have a 4.1 on offense. yet their overall offensive grade is the exact same as the cowboys.
So what does this tell you? The positional rankings are not equal to set offensive or defensive rankings. Should tell you one thing. On one side of the board he is using overall stats Offensive/Defensive = overall while the positional rankings do not add up at all.
Personal conclusion? While i agree with many of these ranks at positional value, I feel some of them are completely broken. That makes this graph a very unique well made, colored toilet paper.