To add, each of these guys has a very narrow and specific job. For instance, one would be focused on 3rd down offense (meaning the offensive plays run by the upcoming opponent on 3rd downs). And these guys get very specific instructions as to what they are expected to deliver, and when (film, stats, tells, etc.). Most of these guys are working a week ahead of the actual schedule, so they deliver their analysis and data immediately after the previous game is played. This allows the coaches and coordinators to use that data immediately in game planning. Sunday morning the coaches have this data in their hands.
These jobs are necessary to compete at the highest level today.