We don't know Cooper can walk right in and start at a position he has very limited experience at. I think he can, but I'm not sold. As I said, we were incredibly fortunate that he fell. He should've been gone in the second. That's luck, not great roster management.
Tyron can't be replaced. Bringing in someone serviceable with the intention of drafting a long term replacement should've been the move. Half right is better than completely wrong, I guess. Guyton will also be switching sides. There's no guarantee of a smooth transition.
So we're looking at a pair of unknowns starting on the line. I'm not worried so much about center. If Cooper can snap the ball, being flanked by Smith and Martin helps a ton. Left tackle is troubling. I'm a Sooner fan. Guyton was a good player in college, but there were very few occasions watching the games where I thought, "holy crap, that guy is a future pro bowler". He has the tools, the frame, and the pedigree. He doesn't have the experience you want from a guy walking into protecting Dak's blindside as a rookie.
You keep wondering why fans like me have concerns. This is why. I don't have faith that this team can fall back on its depth and rookie class to fill the void left by the loss of several key contributors. I hope they prove me wrong, and maybe they will.