I am doing some research on the subject for answers if they exist.

Lepomis reproduce more offspring if well conditioned (lots of food). If you put in small GSF to start a population and feed them they will quickly become reproductive to fill the space and will produce more offspring. Without predation they will continue that process until the carrying capacity of the pond is reached and stunt. That is also true of BG and PS and others except RES (can't find a case of reported RES stunting).