Our 2-3-1 turns into five players behind the ball

I’d stop asking everyone to get back and start asking who actually needs to. If both wide players drop onto the defenders and the centre midfielder joins them, you have numbers behind the ball but no depth between your defensive line and the striker. One wide player might need to recover because the ball is on their side. The far-side player may be more useful staying connected inside or higher. I’d use a directional game where the defending team has to find a target player after winning it. If everybody drops onto the same line, they immediately feel how hard the next pass becomes. At U11, compact does not mean flat. I want the team close enough to help each other while still having somebody connected to the next phase.