Quite a ways back in this conversation, mention was made by at least ewest, esshup, and FishinRod concerning the relative sizes and growth rates among BG, HBG, and GSF.
Let me share observations of mine from our pond and from a friend's pond.
I hand feed Optimal BG once, twice, three times a day depending when the opportunities present themselves. Fish always show up.
BG are most numerous, all sizes, GSF next, the HBG, naturally occurring, the least common. The most common large individuals are GSF; several at 9" to 11" prowl around for pellets and gulp down the occasional cluster of large dried meal worms, preferring the Optimal. The BG rarely take, let alone swallow a pellet of any size. They want broken up meal worms. The HBG grab either, seemingly also preferring the Optimal.
The increased aggression while feeding is obvious, shared by the GSF and HBG, compared to the tea sipping habits of the BG.
Here are some questions, probably hypothetical, about growth and relative size. If the sunfish species that eagerly eat pellets are growing faster than the BG, could it be because they are more aggressive and have wider gapes, allowing them to chose the bigger, denser meals, that is, Optimal pellets?
My other limited observation is from fishing a friend's effectively GSF only pond a few times. There, the range of fish sizes that I've caught runs from the tiniest up through about 8". There may well be larger individuals; the others are so numerous that fishing with two or three hooks yields 2 GSF or 3 GSF on nearly every cast. It's easy to get enough fish for a big meal in 20 minutes, or less.
As and aside, we introduced 21 LMB to the pond several years ago. They must be in heaven. I haven't been back to give the fishing a try since that introduction of Lucky Largemouths.