Hmmm, certainly does look like Brock is evolving as a fighter. But you have to take training vids with a pinch of salt, their purpose is to generate hype around a fighter.
That said, I certainly think Carwin has his hands full. Brock with BJJ is terrifying. Even basic levels become more lethal under a wrestler of his credentials. His core muscles, posture and positioning on top of a wrestling base will make BJJ come much more naturally. Damn, an evolved Brock is a scary thought.
I probably was being sarcastic in the above post. I think you should flame me for it.