I think I would have John use Sequence. With sequence he can best give details to others rather then trying to give jumbled facts. But using both precise and sequence would also be the best route.
Paul should use Sequence when trying to explain how a machine works. Explaining in steps will help others understand what is being said. I would also think Precise would work when giving facts about the machines workings.
Raheem should use Precise more often with his work. Using precise in his writing