Does any body have any thoughts /plan on player rotaion between A,B,C teams. U9's

Does any body have a plan on how and why Squad rotation works when you are running 3 teams, A,B,C to ensure that the best players from the lower teams get to move up and down through the other teams. It is not expected that the C team players will rotate to the a team but we want to try and capture the better players from B and C and rotate them up to the team above.