Dergib - CanyonC has some very good suggestions; heed them. Of course the "pond guy" says he would add a large aerator - $ sales for them. IAerator maybe not necessary in 15acres. If he did not tell you what the names of the weeds were; I would not use them again. IMO no need to sink trees until the weeds are gone or a lot less abundance. Both Sunken trees and weeds are both good habitat. With lots of weeds the pond has plenty of cover maybe TOO much hiding place cover which is why the pond has too many small fish; bas cannot find the hiding fish. Ideally cover should encompass about 25%-30% of the shoreline for producing the best fishery. Sounds like the pond has a lot more weed growth than 30% which becomes too much resulting in too many small fish. IMO more bass and fewer weeds are needed.
Get some GOOD weed pics and of unknown fish. See this from our Archives:
https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=371748#Post371748How big is the small pond and what is the main goal of having it or using it.?
Adding pike or musky could very well end up eating more bass than BG or the other problem fish. IMO you need MORE bass predators not fewer. If you had to eat / swallow everything whole, what would you rather swallow a hot dog or can lid??? A pike knows the difference. Smaller bass are slender bodied (fusiform) similar to hot dogs & sausage.