I think one of the "casualties" in the long run is Gurley. They have him through 2019 and can franchise him in 2020 but then I think going into his 7th season you
have to let him go and hope he gets a massive deal elsewhere and recover a 3rd round comp. pick. VERY few RBs are on the upswing of their careers heading into year 7 and when you have Donald, Goff, Cooks, Joyner, etc. something definitely has to give.
Also, just my opinion but the average number for Donald is
far less important than the guaranteed $$ figure. It's not that Von Miller got a deal averaging over $19M that matters. It's the $70M guaranteed that does. Plus to me part of the sense of urgency of signing Donald is to try and get any of it incorporated into 2018 and then as much as possible in 2019 and 2020 when they have a ton of cap room. Have his numbers go down from there when Goff's kick in so there is minimal overlap. The final 1-2 years of Donald's deal cap-wise will be meaningless.