I have an 18 month old HBG/CC pond. I've stocked HBG twice last year and once this year. I also put in some tilapia this year. My HBG definitely spawned successfully this spring and summer.
I have a hard time getting HSB in this area, so I added five SMB that were 4-6 inches. Time will tell.
I know I've got a lot of yolk sac and fry size fishes of some kind right now. They are still too small for me to tell if they are sunfish or tilapia. I've got them in an aerated bucket in hopes they grow enough in the next few days to determine what they are.