This is dead on accurate. My son (pitcher and 3rd base) was a hired gun for several years.
USSSA isn't really the top organization any longer though. Perfect Game rules the upper age groups now at the highest level of play. The tournaments are HUGE and draw literally hundreds of teams from all over the nation. Best of the best literally. Most of these kids are signed or at least committed by 16 or 17 already.
Then add in the showcase events once they get to be 16 and up for scouting. Even the showcase events have hand picked teams when it comes to the best players being seen by the scouts. Saw it first hand with my son. Every showcase he was invited to was free or discounted heavily and the players were put on their own charter bus for the trip to and from with hotels payed for by the program. The boys played on the same team even though it's supposed to be "randomly" picked teams. Typically to Ft. Myers, Jupiter FL and a few other events in the S.E. US.