Our midfielders never run beyond the strikers

I’d create a reason for the midfielder to recognise the space beyond rather than telling them to make more forward runs. A 4v4+3 directional game can work well. If a striker checks towards the ball, the next midfielder can score an extra point by arriving beyond the line the striker has vacated. Use that condition briefly, then remove it. The midfielder needs to see what the striker’s movement has created. Sometimes running beyond is right. Sometimes staying underneath gives the team a better balance. At U13, the important idea is that one player’s movement should trigger thought in the players around them. If the striker comes short and every midfielder also comes short, the team has solved the same problem three times. Encourage different heights and let the players decide who attacks the new space.