Al in most cases of an existing pond I would not worry about GSH being egg eaters any more than the following fish doing exactly the same (BG , RES , tilapia , LMB and most others). Again it is not easy to establish a GSH population in an existing LMB/BG pond and they can have reproductive problems as well.

TGW it is hard to provide easy tilapia stocking #s as it depends on your water and predator situation. For example stocking 4 inch tilapia into a pond lacking larger forage and full of 3-5 lb. LMB could be a challenge.