I can't imagine that the GSHs would be a problem in your pond if your SM and YP are already 9"+. Some of the other species that others have mentioned may be better options, but I would highly doubt you'd get an excess of 6"+ GSH when your predators are already stocked JMHO.
GSH can absolutely achieve adult sizes in the presence of these apex predators, hence the advice provided by fishery management professionals. This advise isn't provided on a hunch, it's based on management of dozens of fisheries with these species present - some also with HSB and WE, and GSH still routinely achieve adult size - hence the direction based on experience.