But it can be worse to try to do a Musical with many featured parts, but with no way for them to be heard because there are still just a few stationary mics on the stage. Even with some lavaliers on the main characters, the plot can still be lost for the audience. That's where well-planned blocking and staging comes in.
If there are only a couple of mics available, make sure the kid who is talking or singing is right next to one of them. Make sure their crosses to get to the mics make sense. Group the speakers so that they can easily and gracefully get to a mic before they speak, but have them at least try to "walk and talk" getting there. Project!! Use gestures!! Pull focus!!! Cheat out toward the audience!! (I am convinced that most people need to read lips, gestures, and body language to understand actors on stage.)
"Freeze, Frame, Focus" is an acting game used to help young actors learn about Planes, Proximity, Levels, Focus, and creating a good stage Picture. Being aware on stage how close the actors are to each other (proximity), how they are arranged in depth on the stage (planes), how they fill the scene without blocking each other (levels), how they can help throw or pull attention on the pertinent action or character (focus), and how to keep balance on the stage (picture).
How to play: Have the children walk around on stage filling it to the edges. You may play music or give them direction to walk like a "robot," or "Lion," or some other character. When you call Freeze, they all quickly assess where they are on stage. Then you call someone's name as the Focus child.
Everyone else must make a good stage picture (Frame) focussing on that child. If they are standing tall in front, they should make themselves shorter and throw their arms out toward the Focus child. If they are small in back, they should stand as tall as they can and throw their arms toward the Focus child. All of the children should maintain good proximity so everyone can be seen. They should also watch their planes, not bunching up, but filling out the scene.