What I would do is to assign the two coaches different breakdown drills to be practiced at different ends of the court, much like station drills in a camp system. That is how I would handle assistant's assignments in practice. Use your assistant's experience strength's when conducting specific individual skills but share team skills across your assistants. It is not only a way to train them to be observant but to learn the importance of how this data is used via this experience. You'll probably notice that most head coaches who have considerable game experience can almost tell you at any point in time who has how many fouls, how many consecutive possessions the opponent has score or even how much time has transpired since the last points in the paint.
Experience teaches the best coaches who to absorb a lot of detail and how to process it efficiently.
I would use the more experienced assistant coach to push consistent questions about changes in offense and defense but this too depends on how you as a head coach want to interact with your main assistant. If you have two very experienced assistant coaches involve both in your decision making. I know I haven't helped you directly in making your assistant's assignments, but I believe it must be based on the talents and experiences of your coaching staff. I have coached 6 different teams, each of my assistants had different duties based primarily on their knowledge and abilities. One assistant for example wasn't as experienced in game observation and adjustments so they were given many organizational skills while I attempted to teach them game decision making.