I agree that JB (and CA) were very well prepared and rehearsed (scripted). Was ICA following along with the script?
However, you cannot do that for the whole trial, from memory so JB needs to start as he means to go on and prepare notes to follow.
He also needs to try to envision the prosecution side, he'd do well to role play and run through scenarios with his team to be ready. I am not so sure how JB will do on cross and when he has to react on his feet to something un-expected or contentious.
Both CM and JB did not seem to do so well once they did their initial forays, in response and reaction to the SA. Maybe CM did better on that but his accent and style is challenging.
Like my projects, it is all in the planning and preparation ... done well the execution will be flawless and ready for all sorts of developments and surprises. You cannot fly by the seat of your pants .... that will only get you so far.