Stocking tilapia here in Georgia is illegal which is a shame because it is an awesome fish. The FHM wouldn’t benefit you and they would be wiped out in a hurry by the bass. We generally recommend 250-500 3-5” per acre bluegill to boost up the forage. I have even read people stocking well over 500/acre to boost the forage. Without shocking the pond I don’t know how many bass you need to take out but if they are averaging 10” harvest anything 10-12” or less. You can go to our website,
http://www.lakework.com and click on the articles tab and scroll down to the relative weight chart so you can start calculating the Wr of the bass (bass you may think that need to go back into the pond). Also you said that the other pond with the big bass had plenty of structure in it. Does the 3 acre have any? If not you need to add some to let those bluegill grow to bigger sizes so those bass can conserve energy to grow. It sounds like the bluegill recruitment is low, which can be contributed to not enough dense cover (protection) and too many bass. You may also want to consider threadfin shad and even stocking some F1 bass or pure northern bass later down the road to help improve the genetics of the bass. But all in all reduce the bass population (harvest) and increase the forage population (stocking).
