How do you coach players who all run towards a loose ball?

I would give the players two jobs around a loose ball. One player competes for it. Everyone else asks, “If they win it, where can I help? If they lose it, what space needs protecting?” Then put that picture into a small game where loose balls happen often. You can even reward the team for the second action after the contest rather than the contest itself. That helps players see that the football is not over once somebody reaches the ball first. I would avoid shouting “spread out” every time three players collapse on it. They need to understand why somebody staying away can be more useful. At U10, the simple picture is enough: one attacks the loose ball, others prepare for what happens next. That covers both possession and defending without turning it into a tactical lecture.