I am the primary predator of our GSF. It seems to me that you, too, could be an effective reducer of the splendid GSF.
If I believe there's an imbalance between BG and GSF, I sit on the dock for and hour or two and haul them in. Some times it's GSF; other times it's BG. I chum a little to get them coming, then start with a double or triple hook rig on an ultralight spin or a 3 weight fly rod. Baits can be Berkeley Gulp or Powerbait grubs, crappie nibbles, earthworms, Creme trout worms, or nearly any other small rubber type baits. For me it's usual to hook 2 and often 3 sunfish on each cast. My water clarity is good, so I can sight fish for individuals that I'd like to remove.
At this rate you could pull 100, 200, 300 or more GSF out each week and reduce their population quickly.
Fyke nets are useful.
That scrawny bass actually indicates nothing except it hasn't been eating well or digesting its food. It seems there should be many many GSF fry and fingerlings for nearly all the bass in your pond. The opposite predation might also be occuring. The GSF may be gobbling up your young bass, limiting bass recruitment. A very good bait for big GSF in my pond is a 3" to 5" LMB.
I have no experience with WE nor CC in my pond. They both feed at night when YP and GSF tend to be motionless on the bottom so are easy targets.
