There is both a physical and mental component to turnovers. There is also the situation where a great hit directly on the ball occurs, and little can be done about it. Both Mo and Martinez carry the ball outside of their bodies. It is glaring with Mo. He will learn that is an unacceptable way to carry the ball. Both will continue to build physically and mentally and will be better protectors of the ball in the near future.
Remember, Ameer was a fumbler early in his career and he was vastly improved later in his colligent life.