....... it struck me that this (2+ games in one day for diff. teams) likely was not true.
What I was seeing happen was players passed down to "get playing time" for a game, but that would push the lower team's players onto the bench that week. Or at least once where a coach really wanted to "help" the lower flight team, he'd pass down several of the best players -- who then played the whole game while the team's regular kids watched. Probably not how the player passes are supposed to work.
There is a SCDSL rule that prohibits any player playing for more than one team/day. Is the rule ever broken, I don't know but strange things have know to happen time to time.
As for player playing down a level and starting. It happens all the time. Not just players that don't get minutes on their team, looking for additional field time. I have seen Flight 1 starters play on Flight 3 team to secure table position during league play. I've also seem bottom flight 1 players on a team refusing to play down, when offered to gain field time. But, vast majority of the time, its because the team is short of players and the coach goes to upper tier team for help, rather than peer or lower tier team (some clubs only have one in each age group). Other example that often happens is a kid playing up a year and doesn't play as much so the player often guests own age and starts.
Playing time is strictly performance based, especially as they get older. Its really parents job to match the player's level and the team's level. DOCs will simply take the money for team that makes parents happen and let the kid flounder on a high level team. Just make sure that the player is in the top half of the team's level, and not the bottom half....
I know the league is supposed to be for development and often winning is treated like a sin because the coach played better players in the game over "less developed". The truth of the matter is that players that cannot make the right decisions, plays, and turns the ball over is not ready for the speed of plays and pressure at the level. It does nothing to continue with those players in that situation. Often it leads to undermine the development and results in the player liking soccer less and less.
Learning what it takes to win is a very important part of the development, and often is not discussed because its not skills and techniques. The mental and soccer IQ part of the game is often ignored in the "development" discussion. This include putting the individual effort - mentally and physically - to break into the starting 11 on the team.