The NVR isn't quicker than you thought. You were working on the basis of 60 questions in 30 minutes which is the same 30 seconds per question.
The English does equate to much less time per question than you had expected but you still have a little remaining time to work on increasing speed.
The creative writing element is also less time than you expected but try not to worry too much about that as I don't think they can be expecting a great deal of writing to be done in only 20 minutes.
Your child might be glad that he doesn't have to sit for as long as he thought in the exams. Sell it to him as a positive.