As a side note: He absolutly loved playing high school ball. He was amazed how close knit the players were to each other. He commented he was closer to his high school team mates (that he only played with for a few months), than his German teammates that he had played with for years.
My son feels that way about his club team. His club team is our "soccer family". They are together practicing from June until December and in the spring still practice a little and play in several tournaments just to stay together. My son also hangs out with several teammates from different schools even on weekends when they are not playing. Most of the boys have been together for 4 or 5 years and in some cases longer. When you travel most every weekend from August to November you develop a closeness you are describing. They really hang out alot together on these trips and you can see that even though they go to 8 or 10 different high schools they still really like and respect each other.
So I guess my point is club teams can have that close knit feeling even though they don't go to school together.