I believe Strzok is cooperating because he can see exactly what, frankly, anyone paying attention should see...he has been set up to take the biggest fall by his former superiors (Comey, Lynch, Clinton, Obama). He (along with Lisa Page) was set up to be the sacrificial lamb for the higher ups. They were the first fire wall. I suspect its quite possible that Strzok doesnt want to be in that position.
2 phrases come to mind
“no honor among thieves” and “eating their own”
Enjoy the show!
Good reasoning. They both have been teed up to take the fall.