The standard reference (Wiley et.al 1984) for amount of plant cover in ponds for best or optimum (100%) all natural bass and sunfish production is to have 36%-40% maximum plant cover in the shallow areas aka littoral zone. The deep pond basin having no weeds. Weeds just around the shoreline areas maybe down to 5-6ft. . Fish production was still high with 80% fish production having plant cover percentages of 20% to 50% on ether side of the bell shaped curve. Regularly adding fish foods such as fish pellets to the system can enhance the fish production in ponds with low plant coverage.

IMO the more sumerged weeds you can remove from the pond the better the LMB will find, catch and eat GSF. The opposite is true. For initial good GSF control, I think you should basically work each year to kill all the underwater vegetation. Then while you are manually removing every GSF you can, bass eating GSF plus you focus your bass angling on removing the LMB larger than 12"-13". Then after several years ,,when you see evidence of very few remaining GSF and those survivors are basically large individuals (7"-9") then you can allow submerged plants to naturally return or beneficial ones be planted to improve the size classes of panfish. When GSF have been significantly reduced to large individuals, then you can supplimentally stock large individuals of other species of panfish, YP, PSF, Crappie (hybrids), CC.

If you want this problematic fishery to be a quick fix get the entire shallow 3/4 ac pond chemically renovated. It depends on how fast you want this fishery to be revamped and restarted. Renovation costs money but your time and efforts spent for several years getting the fishery turned around also has $$$$ value unless you want to do all this effort as a hobby and your time and efforts have low value. Doing all this for the best outcome could take up to 4 to 5 years.

IMO the long term goal as capital appropriation is to get the pond drained and and properly rebuilt with good deep basin structure to endure northern winters without needed aeartion. Michigan State univ Extension pond managemetn booklet describes best pond basin structure for northern ponds.
https://archive.lib.msu.edu/DMC/extension_publications/e1554/e1554-1989-print2.pdf


Wiley, et.al 1984. The relationship between aquatic macrophytes and sport fish production in Ilinois ponds: a simple model. North Amer. J. Fish Management 4:111-119.