Here are my thoughts on that question: Determining stocking qty all depends on the availability of your forage base, if you are going to supplement with feeding program [which I encourage], presence of other apex predators, and your goals - do you want to harvest some, or leave them to grow to trophy status? IE: High forage base, plus feeding, plus low presence of predators, and harvest plan = higher qty/acre stocking. And this works inversely, obviously, also.
Some other considerations: If your resident LMB are large you'll need to stock advanced HSB fingerlings to avoid predation from LMB. If your LMB are small - you can get away with stocking higher qty of smaller, cheaper HSB, and they won't end up serving as a snack for the green carp...er, LMB.