Can you post photos of the HBG you are catching? Curious if they are in fact HBG or another sunfish species or combination there of.

In ponds less than a couple areas in size, I like a HBG/HSB/CC combination. You could add 25-50 CC and 10-20 HSB to the pond. That should help control the reproduction of the HBG. Pray the BC are dead and do not reproduce. If they do, you'll have a serious management challenge.