The problem wasnt Castillo. It was the dummies like Gino and Oher that couldn't learn his system which worked great in Philly for years. Yanda ended up with the line calls because he was the only dude that learned it. HARBs had Gino sitting in the first row of the line meetings taking notes while he watched in the back.
You gotta have the players that can learn the ZBS and Castillo has a very difficult scheme to learn but it worked in Philly. He was one of the best line coaches in the game.
As for Caldwell, there were plenty of posters here that had doubts from the beginning.
As for Kubes, he was a head coach for years and an o-coord for years before that and a QB for years before that. His system is proven and his ZBS is easier to learn. He won't be making the lousy play calling that Caldwell did. We even have his TE from Houston who is much better than Dallas Clark was last year.
Wait til you see Daniels and Pitta hitting the middle from opposite sides at the same time after Torrey and JJ take their guys deep and Steve Smith underneath of them.
It's gonna be an exciting offense.