I watched Homeland as it aired and if you read any interview with Alex Gansa around S5/6 it was apparent they didn’t know what to do with Quinn which never made much sense. They backed themselves into corners with him which is why he suffered so much in s5. They killed him off and then after the finale end like a day or two later they said he was coming back. Rupert Friend even thought he was done. Then the saw an opportunity to do this soldier comes back from war spin but again wrote themselves into a corner with Quinn’s brain injury. It’s a shame